patch (for 9.1) string functions

*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-03-09 13:28:17.082096569 +0100
--- ./contrib/stringfunc/expected/stringfunc.out	2010-03-09 19:44:22.672219719 +0100
***************
*** 0 ****
--- 1,160 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+            concat           
+ ----------------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+            concat_sql           
+ --------------------------------
+  1,2,3,'hello',t,f,'03-09-2010'
+ (1 row)
+ 
+ select concat_json(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+               concat_json              
+ ---------------------------------------
+  1,2,3,"hello",true,false,"03-09-2010"
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select rvrs('abcde');
+  rvrs  
+ -------
+  edcba
+ (1 row)
+ 
+ select left('ahoj', 2);
+  left 
+ ------
+  ah
+ (1 row)
+ 
+ select left('ahoj', 5);
+  left 
+ ------
+  ahoj
+ (1 row)
+ 
+ select left('ahoj', 0);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select left('ahoj', -1);
+  left 
+ ------
+  aho
+ (1 row)
+ 
+ select left('ahoj', -10);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select right('ahoj', 2);
+  right 
+ -------
+  oj
+ (1 row)
+ 
+ select right('ahoj', 5);
+  right 
+ -------
+  ahoj
+ (1 row)
+ 
+ select right('ahoj', 0);
+  right 
+ -------
+  
+ (1 row)
+ 
+ select right('ahoj', -1);
+  right 
+ -------
+  hoj
+ (1 row)
+ 
+ select right('ahoj', -10);
+  right 
+ -------
+  
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-03-05 15:05:20.171741922 +0100
--- ./contrib/stringfunc/Makefile	2010-03-05 14:34:31.391738508 +0100
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-03-09 13:14:14.064096132 +0100
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-03-09 14:02:05.999094713 +0100
***************
*** 0 ****
--- 1,44 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('%010d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_json(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select rvrs('abcde');
+ 
+ select left('ahoj', 2);
+ select left('ahoj', 5);
+ select left('ahoj', 0);
+ select left('ahoj', -1);
+ select left('ahoj', -10);
+ 
+ select right('ahoj', 2);
+ select right('ahoj', 5);
+ select right('ahoj', 0);
+ select right('ahoj', -1);
+ select right('ahoj', -10);
*** ./contrib/stringfunc/stringfunc.c.orig	2010-03-05 15:05:30.876738040 +0100
--- ./contrib/stringfunc/stringfunc.c	2010-03-09 19:43:56.480094774 +0100
***************
*** 0 ****
--- 1,1024 ----
+ #include "postgres.h"
+ #include "stdio.h"
+ #include "wchar.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ #include "utils/memutils.h"
+ #include "utils/pg_locale.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_format(PG_FUNCTION_ARGS);
+ Datum	stringfunc_format_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_json(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_sql(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_right(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_rvrs(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_format);
+ PG_FUNCTION_INFO_V1(stringfunc_format_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_json);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_sql);
+ PG_FUNCTION_INFO_V1(stringfunc_rvrs);
+ PG_FUNCTION_INFO_V1(stringfunc_left);
+ PG_FUNCTION_INFO_V1(stringfunc_right);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ /*
+  * Static functions
+  */
+ static char *json_string(char *str);
+ static int mb_string_info(text *str, char **sizes, int **positions);
+ 
+ /*
+  * External
+  */
+ extern PGDLLIMPORT char *days[];
+ 
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 						elog(NOTICE, "1");
+ 					}
+ 					else
+ 					{
+ 						bool valid = false;
+ 					
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 							valid = true;
+ 						}
+ 						
+ 						if (!valid)
+ 							ereport(ERROR,
+ 								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 								 errmsg("broken sprinf format"),
+ 								 errdetail("missing precision value")));
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprinf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 		
+ 	if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters")));
+ 						 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 							const char 		*format;
+ 							Oid                     typoutput;
+ 							bool            typIsVarlena;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							format = currentFormat(&format_str, &pdesc);
+ 
+ 							/* use wide chars if it is necessary */
+ 							if (pg_database_encoding_max_length() > 1)
+ 							{
+ 								wchar_t *wformat;
+ 								wchar_t	*wbuffer;
+ 								size_t 	fmtlen = (strlen(format) + 1) * sizeof(wchar_t);
+ 								size_t	len = strlen(target_value) + 1;
+ 								
+ 								wformat = palloc(fmtlen);
+ 								char2wchar(wformat, fmtlen, format, strlen(format));
+ 								wbuffer = palloc(len * sizeof(wchar_t));
+ 								
+ 								for (;;)
+ 								{
+ 									int	result;
+ 									
+ 									if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, 
+ 															 pdesc.precision, target_value);
+ 									else if (pdesc.flags & stringfunc_WIDTH)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, target_value);
+ 									else if (pdesc.flags & stringfunc_PRECISION)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.precision, target_value);
+ 									else
+ 										result = swprintf(wbuffer, len, wformat, target_value);
+ 									
+ 									if (result != -1)
+ 									{
+ 										/* append result */
+ 										appendStringInfo(&str, "%ls", wbuffer);
+ 										break;
+ 									}
+ 									else
+ 									{
+ 										/* increase buffer size and repeat */
+ 										len *= 2;
+ 										if ((len * sizeof(pg_wchar)) > MaxAllocSize)
+ 											ereport(ERROR,
+ 												(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ 												 errmsg("out of memory")));
+ 												 
+ 										wbuffer = repalloc(wbuffer, len * sizeof(wchar_t) + 1);
+ 										/* continue */
+ 									}
+ 								}
+ 								
+ 								pfree(wbuffer);
+ 								pfree(wformat);
+ 							}
+ 							else
+ 							{
+ 								/* shortcut for one byte encoding */
+ 								if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 									appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 								else if (pdesc.flags & stringfunc_WIDTH)
+ 									appendStringInfo(&str, format, pdesc.width, target_value);
+ 								else if (pdesc.flags & stringfunc_PRECISION)
+ 									appendStringInfo(&str, format, pdesc.precision, target_value);
+ 								else
+ 									appendStringInfo(&str, format, target_value);
+ 								
+ 								pfree(target_value);
+ 							}
+ 						}
+ 						break;
+ 				}
+ 			}
+ 			else
+ 				/* return null when some argument is null */
+ 				PG_RETURN_NULL();
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 1)
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 1)
+ 			appendStringInfoString(&str, sepstr);
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat string with respect to SQL format. This is NULL safe.
+  * NULLs values are transformated to "NULL" string.
+  */
+ Datum
+ stringfunc_concat_sql(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData		str;
+ 	text *result;
+ 	int	i;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 0)
+ 			appendStringInfoChar(&str, ',');
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 			TYPCATEGORY	typcat;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			typcat = TypeCategory(valtype);
+ 
+ 			if (typcat == 'N' || typcat == 'B')
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 			{
+ 				text	*txt;
+ 				text	*quoted_txt;
+ 			
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				
+ 				/* get text value and quotize */
+ 				txt = cstring_to_text(OidOutputFunctionCall(typoutput, value));
+ 				quoted_txt = DatumGetTextP(DirectFunctionCall1(quote_literal,
+ 											    PointerGetDatum(txt)));
+ 				appendStringInfoString(&str, text_to_cstring(quoted_txt));
+ 			}
+ 		}
+ 		else
+ 			appendStringInfoString(&str, "NULL");
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Concat string with respect to JSON format. This is NULL safe.
+  * NULLs values are transformated to "null" string.
+  * JSON uses lowercase characters for boolean constants - see www.json.org
+  */
+ Datum
+ stringfunc_concat_json(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData	str;
+ 	text	*result;
+ 	int i;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 0)
+ 			appendStringInfoChar(&str, ',');
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 			TYPCATEGORY	typcat;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			typcat = TypeCategory(valtype);
+ 
+ 			if (typcat == 'N')
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			} else if (typcat == 'B')
+ 			{
+ 				bool	bvalue = PG_GETARG_BOOL(i);
+ 				
+ 				appendStringInfoString(&str, bvalue ? "true" : "false");
+ 			}
+ 			else
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfo(&str, "\"%s\"", json_string(OidOutputFunctionCall(typoutput, value)));			
+ 			}
+ 		}
+ 		else
+ 			appendStringInfoString(&str, "null");
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ stringfunc_left(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(cstring_to_text(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, positions[n - 1] + sizes[n - 1]);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, positions[len - n - 1] + sizes[len - n - 1]);
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ stringfunc_right(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(CStringGetTextDatum(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + positions[len - n],
+ 								positions[len - 1] + sizes[len - 1] - positions[len - n]);
+ 		}
+ 		else
+ 		{
+ 			if (-n < len)
+ 			{
+ 				n = -n > len ? len : -n;
+ 				result = cstring_to_text_with_len(p + positions[n],
+ 									positions[len - 1] + sizes[len - 1] - positions[n]);
+ 			}
+ 			else
+ 			{
+ 				/* return empty string */
+ 				result = cstring_to_text_with_len("", 0);
+ 			}
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + len - n, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p + n, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ stringfunc_rvrs(PG_FUNCTION_ARGS)
+ {
+ 	text *str;
+ 	text	*result;
+ 	char	*p;
+ 	int  len;
+ 	char	*data;
+ 	int		i;
+ 
+ 	str = PG_GETARG_TEXT_PP(0);
+ 	p = VARDATA_ANY(str);
+ 	len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	data = (char*) VARDATA(result);
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		/* multibyte version */
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		for (i = len - 1; i >= 0; i--)
+ 		{
+ 			memcpy(data, p + positions[i], sizes[i]);
+ 			data += sizes[i];
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		for (i = len - 1; i >= 0; i--)
+ 			*data++ = p[i];
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Convert C string to JSON string
+  */
+ static char *
+ json_string(char *str)
+ {
+ 	char	len = strlen(str);
+ 	char		*result, *wc;
+ 	
+ 	wc = result = palloc(len * 2 + 1);
+ 	while (*str != '\0')
+ 	{
+ 		char	c = *str++;
+ 		
+ 		switch (c)
+ 		{
+ 			case '\t':
+ 				*wc++ = '\\';
+ 				*wc++ = 't';
+ 				break;
+ 			case '\b':
+ 				*wc++ = '\\';
+ 				*wc++ = 'b';
+ 				break;
+ 			case '\n':
+ 				*wc++ = '\\';
+ 				*wc++ = 'n';
+ 				break;
+ 			case '\r':
+ 				*wc++ = '\\';
+ 				*wc++ = 'r';
+ 				break;
+ 			case '\\':
+ 				*wc++ = '\\';
+ 				*wc++ = '\\';
+ 				break;
+ 			case '"':
+ 				*wc++ = '\\';
+ 				*wc++ = '"';
+ 				break;
+ 			default:
+ 				*wc++ = c;
+ 		}
+ 	}
+ 	*wc = '\0';
+ 	return result;
+ }
+ 
+ /*
+  * Returns length of string, size and position of every
+  * multibyte char in string.
+  */
+ static int
+ mb_string_info(text *str, char **sizes, int **positions)
+ {
+ 	int r_len;
+ 	int cur_size = 0;
+ 	int sz;
+ 	char *p;
+ 	int cur = 0;
+ 
+ 	p = VARDATA_ANY(str);
+ 	r_len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	if (NULL != sizes)
+ 		*sizes = palloc(r_len * sizeof(char));
+ 	if (NULL != positions)
+ 		*positions = palloc(r_len * sizeof(int));
+ 
+ 	while (cur < r_len)
+ 	{
+ 		sz = pg_mblen(p);
+ 		if (sizes)
+ 			(*sizes)[cur_size] = sz;
+ 		if (positions)
+ 			(*positions)[cur_size] = cur;
+ 		cur += sz;
+ 		p += sz;
+ 		cur_size += 1;
+ 	}
+ 
+ 	return cur_size;
+ }
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-03-05 15:05:47.260738126 +0100
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-03-09 13:27:00.146096268 +0100
***************
*** 0 ****
--- 1,9 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat(VARIADIC args "any");
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
+ DROP FUNCTION concat_json(VARIADIC args "any");
+ DROP FUNCTION concat_sql(VARIADIC args "any");
+ DROP FUNCTION rvrs(str text);
+ DROP FUNCTION left(str text, n int);
+ DROP FUNCTION right(str text, n int);
*** ./doc/src/sgml/contrib.sgml.orig	2010-01-29 00:59:52.000000000 +0100
--- ./doc/src/sgml/contrib.sgml	2010-03-05 15:12:18.861738045 +0100
***************
*** 113,118 ****
--- 113,119 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-02-22 12:47:30.000000000 +0100
--- ./doc/src/sgml/filelist.sgml	2010-03-09 15:04:46.210861483 +0100
***************
*** 123,128 ****
--- 123,129 ----
  <!entity pgstattuple     SYSTEM "pgstattuple.sgml">
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-03-03 23:28:42.000000000 +0100
--- ./doc/src/sgml/func.sgml	2010-03-05 14:28:25.807765920 +0100
***************
*** 1262,1267 ****
--- 1262,1270 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
***************
*** 1450,1455 ****
--- 1453,1473 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-03-05 15:11:23.284738364 +0100
--- ./doc/src/sgml/stringfunc.sgml	2010-03-09 15:10:43.378094796 +0100
***************
*** 0 ****
--- 1,79 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat(param1 [, param2 [,...]])</> a concation two or more strings
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_json(param1 [, param2 [,...]])</> a concation two or more
+       strings. Values are converted to JSON format.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_sql(param1 [, param2 [,...]])</> a concation two or more
+       strings. Values are converted to format of SQL constants.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>rvrs(str)</> reverse a string
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>left(str, n)</> returns n chars from start. When n is negative, then 
+       returns chars without last n chars.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>right(str, n)</> return last n chars. When n is negative, then 
+       returns chars without first n chars.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-02-26 03:01:10.000000000 +0100
--- ./src/backend/utils/adt/varlena.c	2010-03-05 13:08:46.299862167 +0100
***************
*** 3415,3417 ****
--- 3415,3504 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				appendStringInfoString(&str, "NULL");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-02-26 03:01:21.000000000 +0100
--- ./src/include/catalog/pg_proc.h	2010-03-05 14:03:17.995737254 +0100
***************
*** 2712,2717 ****
--- 2712,2721 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f i 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-02-26 03:01:28.000000000 +0100
--- ./src/include/utils/builtins.h	2010-03-05 13:13:24.979862366 +0100
***************
*** 730,735 ****
--- 730,738 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/expected/text.out	2010-03-05 14:09:47.000000000 +0100
***************
*** 51,53 ****
--- 51,76 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters
+ select format('Hello',10);
+ ERROR:  too many parameters
*** ./src/test/regress/sql/text.sql.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/sql/text.sql	2010-03-05 14:09:34.083738128 +0100
***************
*** 28,30 ****
--- 28,39 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 

*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-03-09 13:28:17.082096569 +0100
--- ./contrib/stringfunc/expected/stringfunc.out	2010-03-09 19:44:22.672219719 +0100
***************
*** 0 ****
--- 1,160 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+            concat           
+ ----------------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+            concat_sql           
+ --------------------------------
+  1,2,3,'hello',t,f,'03-09-2010'
+ (1 row)
+ 
+ select concat_json(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+               concat_json              
+ ---------------------------------------
+  1,2,3,"hello",true,false,"03-09-2010"
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select rvrs('abcde');
+  rvrs  
+ -------
+  edcba
+ (1 row)
+ 
+ select left('ahoj', 2);
+  left 
+ ------
+  ah
+ (1 row)
+ 
+ select left('ahoj', 5);
+  left 
+ ------
+  ahoj
+ (1 row)
+ 
+ select left('ahoj', 0);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select left('ahoj', -1);
+  left 
+ ------
+  aho
+ (1 row)
+ 
+ select left('ahoj', -10);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select right('ahoj', 2);
+  right 
+ -------
+  oj
+ (1 row)
+ 
+ select right('ahoj', 5);
+  right 
+ -------
+  ahoj
+ (1 row)
+ 
+ select right('ahoj', 0);
+  right 
+ -------
+  
+ (1 row)
+ 
+ select right('ahoj', -1);
+  right 
+ -------
+  hoj
+ (1 row)
+ 
+ select right('ahoj', -10);
+  right 
+ -------
+  
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-03-05 15:05:20.171741922 +0100
--- ./contrib/stringfunc/Makefile	2010-03-05 14:34:31.391738508 +0100
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-03-09 13:14:14.064096132 +0100
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-03-09 14:02:05.999094713 +0100
***************
*** 0 ****
--- 1,44 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('%010d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_json(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select rvrs('abcde');
+ 
+ select left('ahoj', 2);
+ select left('ahoj', 5);
+ select left('ahoj', 0);
+ select left('ahoj', -1);
+ select left('ahoj', -10);
+ 
+ select right('ahoj', 2);
+ select right('ahoj', 5);
+ select right('ahoj', 0);
+ select right('ahoj', -1);
+ select right('ahoj', -10);
*** ./contrib/stringfunc/stringfunc.c.orig	2010-03-05 15:05:30.876738040 +0100
--- ./contrib/stringfunc/stringfunc.c	2010-07-08 13:04:13.458422094 +0200
***************
*** 0 ****
--- 1,1020 ----
+ #include "postgres.h"
+ #include "stdio.h"
+ #include "wchar.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ #include "utils/memutils.h"
+ #include "utils/pg_locale.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_json(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_sql(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_right(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_rvrs(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_json);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_sql);
+ PG_FUNCTION_INFO_V1(stringfunc_rvrs);
+ PG_FUNCTION_INFO_V1(stringfunc_left);
+ PG_FUNCTION_INFO_V1(stringfunc_right);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ /*
+  * Static functions
+  */
+ static char *json_string(char *str);
+ static int mb_string_info(text *str, char **sizes, int **positions);
+ 
+ /*
+  * External
+  */
+ extern PGDLLIMPORT char *days[];
+ 
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 						elog(NOTICE, "1");
+ 					}
+ 					else
+ 					{
+ 						bool valid = false;
+ 					
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 							valid = true;
+ 						}
+ 						
+ 						if (!valid)
+ 							ereport(ERROR,
+ 								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 								 errmsg("broken sprinf format"),
+ 								 errdetail("missing precision value")));
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprinf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 		
+ 	if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters specified for printf function")));
+ 						 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 							const char 		*format;
+ 							Oid                     typoutput;
+ 							bool            typIsVarlena;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							format = currentFormat(&format_str, &pdesc);
+ 
+ 							/* use wide chars if it is necessary */
+ 							if (pg_database_encoding_max_length() > 1)
+ 							{
+ 								wchar_t *wformat;
+ 								wchar_t	*wbuffer;
+ 								size_t 	fmtlen = (strlen(format) + 1) * sizeof(wchar_t);
+ 								size_t	len = strlen(target_value) + 1;
+ 								
+ 								wformat = palloc(fmtlen);
+ 								char2wchar(wformat, fmtlen, format, strlen(format));
+ 								wbuffer = palloc(len * sizeof(wchar_t));
+ 								
+ 								for (;;)
+ 								{
+ 									int	result;
+ 									
+ 									if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, 
+ 															 pdesc.precision, target_value);
+ 									else if (pdesc.flags & stringfunc_WIDTH)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, target_value);
+ 									else if (pdesc.flags & stringfunc_PRECISION)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.precision, target_value);
+ 									else
+ 										result = swprintf(wbuffer, len, wformat, target_value);
+ 									
+ 									if (result != -1)
+ 									{
+ 										/* append result */
+ 										appendStringInfo(&str, "%ls", wbuffer);
+ 										break;
+ 									}
+ 									else
+ 									{
+ 										/* increase buffer size and repeat */
+ 										len *= 2;
+ 										if ((len * sizeof(pg_wchar)) > MaxAllocSize)
+ 											ereport(ERROR,
+ 												(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ 												 errmsg("out of memory")));
+ 												 
+ 										wbuffer = repalloc(wbuffer, len * sizeof(wchar_t) + 1);
+ 										/* continue */
+ 									}
+ 								}
+ 								
+ 								pfree(wbuffer);
+ 								pfree(wformat);
+ 							}
+ 							else
+ 							{
+ 								/* shortcut for one byte encoding */
+ 								if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 									appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 								else if (pdesc.flags & stringfunc_WIDTH)
+ 									appendStringInfo(&str, format, pdesc.width, target_value);
+ 								else if (pdesc.flags & stringfunc_PRECISION)
+ 									appendStringInfo(&str, format, pdesc.precision, target_value);
+ 								else
+ 									appendStringInfo(&str, format, target_value);
+ 								
+ 								pfree(target_value);
+ 							}
+ 						}
+ 						break;
+ 				}
+ 			}
+ 			else
+ 				/* return null when some argument is null */
+ 				PG_RETURN_NULL();
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 1)
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 1)
+ 			appendStringInfoString(&str, sepstr);
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat string with respect to SQL format. This is NULL safe.
+  * NULLs values are transformated to "NULL" string.
+  */
+ Datum
+ stringfunc_concat_sql(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData		str;
+ 	text *result;
+ 	int	i;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 0)
+ 			appendStringInfoChar(&str, ',');
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 			TYPCATEGORY	typcat;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			typcat = TypeCategory(valtype);
+ 
+ 			if (typcat == 'N' || typcat == 'B')
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 			{
+ 				text	*txt;
+ 				text	*quoted_txt;
+ 			
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				
+ 				/* get text value and quotize */
+ 				txt = cstring_to_text(OidOutputFunctionCall(typoutput, value));
+ 				quoted_txt = DatumGetTextP(DirectFunctionCall1(quote_literal,
+ 											    PointerGetDatum(txt)));
+ 				appendStringInfoString(&str, text_to_cstring(quoted_txt));
+ 			}
+ 		}
+ 		else
+ 			appendStringInfoString(&str, "NULL");
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Concat string with respect to JSON format. This is NULL safe.
+  * NULLs values are transformated to "null" string.
+  * JSON uses lowercase characters for boolean constants - see www.json.org
+  */
+ Datum
+ stringfunc_concat_json(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData	str;
+ 	text	*result;
+ 	int i;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 0)
+ 			appendStringInfoChar(&str, ',');
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 			TYPCATEGORY	typcat;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			typcat = TypeCategory(valtype);
+ 
+ 			if (typcat == 'N')
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			} else if (typcat == 'B')
+ 			{
+ 				bool	bvalue = PG_GETARG_BOOL(i);
+ 				
+ 				appendStringInfoString(&str, bvalue ? "true" : "false");
+ 			}
+ 			else
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfo(&str, "\"%s\"", json_string(OidOutputFunctionCall(typoutput, value)));			
+ 			}
+ 		}
+ 		else
+ 			appendStringInfoString(&str, "null");
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ stringfunc_left(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(cstring_to_text(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, positions[n - 1] + sizes[n - 1]);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, positions[len - n - 1] + sizes[len - n - 1]);
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ stringfunc_right(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(CStringGetTextDatum(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + positions[len - n],
+ 								positions[len - 1] + sizes[len - 1] - positions[len - n]);
+ 		}
+ 		else
+ 		{
+ 			if (-n < len)
+ 			{
+ 				n = -n > len ? len : -n;
+ 				result = cstring_to_text_with_len(p + positions[n],
+ 									positions[len - 1] + sizes[len - 1] - positions[n]);
+ 			}
+ 			else
+ 			{
+ 				/* return empty string */
+ 				result = cstring_to_text_with_len("", 0);
+ 			}
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + len - n, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p + n, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ stringfunc_rvrs(PG_FUNCTION_ARGS)
+ {
+ 	text *str;
+ 	text	*result;
+ 	char	*p;
+ 	int  len;
+ 	char	*data;
+ 	int		i;
+ 
+ 	str = PG_GETARG_TEXT_PP(0);
+ 	p = VARDATA_ANY(str);
+ 	len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	data = (char*) VARDATA(result);
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		/* multibyte version */
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		for (i = len - 1; i >= 0; i--)
+ 		{
+ 			memcpy(data, p + positions[i], sizes[i]);
+ 			data += sizes[i];
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		for (i = len - 1; i >= 0; i--)
+ 			*data++ = p[i];
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Convert C string to JSON string
+  */
+ static char *
+ json_string(char *str)
+ {
+ 	char	len = strlen(str);
+ 	char		*result, *wc;
+ 	
+ 	wc = result = palloc(len * 2 + 1);
+ 	while (*str != '\0')
+ 	{
+ 		char	c = *str++;
+ 		
+ 		switch (c)
+ 		{
+ 			case '\t':
+ 				*wc++ = '\\';
+ 				*wc++ = 't';
+ 				break;
+ 			case '\b':
+ 				*wc++ = '\\';
+ 				*wc++ = 'b';
+ 				break;
+ 			case '\n':
+ 				*wc++ = '\\';
+ 				*wc++ = 'n';
+ 				break;
+ 			case '\r':
+ 				*wc++ = '\\';
+ 				*wc++ = 'r';
+ 				break;
+ 			case '\\':
+ 				*wc++ = '\\';
+ 				*wc++ = '\\';
+ 				break;
+ 			case '"':
+ 				*wc++ = '\\';
+ 				*wc++ = '"';
+ 				break;
+ 			default:
+ 				*wc++ = c;
+ 		}
+ 	}
+ 	*wc = '\0';
+ 	return result;
+ }
+ 
+ /*
+  * Returns length of string, size and position of every
+  * multibyte char in string.
+  */
+ static int
+ mb_string_info(text *str, char **sizes, int **positions)
+ {
+ 	int r_len;
+ 	int cur_size = 0;
+ 	int sz;
+ 	char *p;
+ 	int cur = 0;
+ 
+ 	p = VARDATA_ANY(str);
+ 	r_len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	if (NULL != sizes)
+ 		*sizes = palloc(r_len * sizeof(char));
+ 	if (NULL != positions)
+ 		*positions = palloc(r_len * sizeof(int));
+ 
+ 	while (cur < r_len)
+ 	{
+ 		sz = pg_mblen(p);
+ 		if (sizes)
+ 			(*sizes)[cur_size] = sz;
+ 		if (positions)
+ 			(*positions)[cur_size] = cur;
+ 		cur += sz;
+ 		p += sz;
+ 		cur_size += 1;
+ 	}
+ 
+ 	return cur_size;
+ }
*** ./contrib/stringfunc/stringfunc.sql.in.orig	2010-07-08 11:27:31.877299385 +0200
--- ./contrib/stringfunc/stringfunc.sql.in	2010-03-09 13:27:16.618094628 +0100
***************
*** 0 ****
--- 1,44 ----
+ CREATE OR REPLACE FUNCTION sprintf(fmt text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION sprintf(fmt text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf_nv'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat(VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_ws(separator text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_ws'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_json(VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_json'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_sql(VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_sql'
+ LANGUAGE C IMMUTABLE;
+ 
+ CREATE OR REPLACE FUNCTION rvrs(str text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_rvrs'
+ LANGUAGE C IMMUTABLE STRICT;
+ 
+ CREATE OR REPLACE FUNCTION left(str text, n int)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_left'
+ LANGUAGE C IMMUTABLE STRICT;
+ 
+ CREATE OR REPLACE FUNCTION right(str text, n int)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_right'
+ LANGUAGE C IMMUTABLE STRICT;
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-03-05 15:05:47.260738126 +0100
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-03-09 13:27:00.146096268 +0100
***************
*** 0 ****
--- 1,9 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat(VARIADIC args "any");
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
+ DROP FUNCTION concat_json(VARIADIC args "any");
+ DROP FUNCTION concat_sql(VARIADIC args "any");
+ DROP FUNCTION rvrs(str text);
+ DROP FUNCTION left(str text, n int);
+ DROP FUNCTION right(str text, n int);
*** ./doc/src/sgml/contrib.sgml.orig	2010-01-29 00:59:52.000000000 +0100
--- ./doc/src/sgml/contrib.sgml	2010-03-05 15:12:18.861738045 +0100
***************
*** 113,118 ****
--- 113,119 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-02-22 12:47:30.000000000 +0100
--- ./doc/src/sgml/filelist.sgml	2010-03-09 15:04:46.210861483 +0100
***************
*** 123,128 ****
--- 123,129 ----
  <!entity pgstattuple     SYSTEM "pgstattuple.sgml">
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-03-03 23:28:42.000000000 +0100
--- ./doc/src/sgml/func.sgml	2010-03-05 14:28:25.807765920 +0100
***************
*** 1262,1267 ****
--- 1262,1270 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
***************
*** 1450,1455 ****
--- 1453,1473 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-03-05 15:11:23.284738364 +0100
--- ./doc/src/sgml/stringfunc.sgml	2010-03-09 15:10:43.378094796 +0100
***************
*** 0 ****
--- 1,79 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat(param1 [, param2 [,...]])</> a concation two or more strings
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_json(param1 [, param2 [,...]])</> a concation two or more
+       strings. Values are converted to JSON format.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_sql(param1 [, param2 [,...]])</> a concation two or more
+       strings. Values are converted to format of SQL constants.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>rvrs(str)</> reverse a string
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>left(str, n)</> returns n chars from start. When n is negative, then 
+       returns chars without last n chars.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>right(str, n)</> return last n chars. When n is negative, then 
+       returns chars without first n chars.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-02-26 03:01:10.000000000 +0100
--- ./src/backend/utils/adt/varlena.c	2010-07-08 13:06:52.372551690 +0200
***************
*** 3415,3417 ****
--- 3415,3504 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters for format function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				appendStringInfoString(&str, "NULL");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-02-26 03:01:21.000000000 +0100
--- ./src/include/catalog/pg_proc.h	2010-03-05 14:03:17.995737254 +0100
***************
*** 2712,2717 ****
--- 2712,2721 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f i 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-02-26 03:01:28.000000000 +0100
--- ./src/include/utils/builtins.h	2010-03-05 13:13:24.979862366 +0100
***************
*** 730,735 ****
--- 730,738 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/expected/text.out	2010-03-05 14:09:47.000000000 +0100
***************
*** 51,53 ****
--- 51,76 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters
+ select format('Hello',10);
+ ERROR:  too many parameters
*** ./src/test/regress/sql/text.sql.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/sql/text.sql	2010-03-05 14:09:34.083738128 +0100
***************
*** 28,30 ****
--- 28,39 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 

*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-03-09 13:28:17.082096569 +0100
--- ./contrib/stringfunc/expected/stringfunc.out	2010-07-09 10:27:50.000000000 +0200
***************
*** 0 ****
--- 1,154 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+            concat_sql           
+ --------------------------------
+  1,2,3,'hello',t,f,'03-09-2010'
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select left('ahoj', 2);
+  left 
+ ------
+  ah
+ (1 row)
+ 
+ select left('ahoj', 5);
+  left 
+ ------
+  ahoj
+ (1 row)
+ 
+ select left('ahoj', 0);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select left('ahoj', -1);
+  left 
+ ------
+  aho
+ (1 row)
+ 
+ select left('ahoj', -10);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select right('ahoj', 2);
+  right 
+ -------
+  oj
+ (1 row)
+ 
+ select right('ahoj', 5);
+  right 
+ -------
+  ahoj
+ (1 row)
+ 
+ select right('ahoj', 0);
+  right 
+ -------
+  
+ (1 row)
+ 
+ select right('ahoj', -1);
+  right 
+ -------
+  hoj
+ (1 row)
+ 
+ select right('ahoj', -10);
+  right 
+ -------
+  
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-03-05 15:05:20.171741922 +0100
--- ./contrib/stringfunc/Makefile	2010-03-05 14:34:31.391738508 +0100
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-03-09 13:14:14.064096132 +0100
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-07-09 10:23:49.319828876 +0200
***************
*** 0 ****
--- 1,43 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('%010d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_sql(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ 
+ select left('ahoj', 2);
+ select left('ahoj', 5);
+ select left('ahoj', 0);
+ select left('ahoj', -1);
+ select left('ahoj', -10);
+ 
+ select right('ahoj', 2);
+ select right('ahoj', 5);
+ select right('ahoj', 0);
+ select right('ahoj', -1);
+ select right('ahoj', -10);
*** ./contrib/stringfunc/stringfunc.c.orig	2010-03-05 15:05:30.876738040 +0100
--- ./contrib/stringfunc/stringfunc.c	2010-07-09 10:57:30.203297431 +0200
***************
*** 0 ****
--- 1,905 ----
+ #include "postgres.h"
+ #include "stdio.h"
+ #include "wchar.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ #include "utils/memutils.h"
+ #include "utils/pg_locale.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_sql(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_right(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_reverse(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_sql);
+ PG_FUNCTION_INFO_V1(stringfunc_reverse);
+ PG_FUNCTION_INFO_V1(stringfunc_left);
+ PG_FUNCTION_INFO_V1(stringfunc_right);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ /*
+  * Static functions
+  */
+ static int mb_string_info(text *str, char **sizes, int **positions);
+ 
+ /*
+  * External
+  */
+ extern PGDLLIMPORT char *days[];
+ 
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 						elog(NOTICE, "1");
+ 					}
+ 					else
+ 					{
+ 						bool valid = false;
+ 					
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 							valid = true;
+ 						}
+ 						
+ 						if (!valid)
+ 							ereport(ERROR,
+ 								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 								 errmsg("broken sprinf format"),
+ 								 errdetail("missing precision value")));
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprinf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 		
+ 	if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters specified for printf function")));
+ 						 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 							const char 		*format;
+ 							Oid                     typoutput;
+ 							bool            typIsVarlena;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							format = currentFormat(&format_str, &pdesc);
+ 
+ 							/* use wide chars if it is necessary */
+ 							if (pg_database_encoding_max_length() > 1)
+ 							{
+ 								wchar_t *wformat;
+ 								wchar_t	*wbuffer;
+ 								size_t 	fmtlen = (strlen(format) + 1) * sizeof(wchar_t);
+ 								size_t	len = strlen(target_value) + 1;
+ 								
+ 								wformat = palloc(fmtlen);
+ 								char2wchar(wformat, fmtlen, format, strlen(format));
+ 								wbuffer = palloc(len * sizeof(wchar_t));
+ 								
+ 								for (;;)
+ 								{
+ 									int	result;
+ 									
+ 									if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, 
+ 															 pdesc.precision, target_value);
+ 									else if (pdesc.flags & stringfunc_WIDTH)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.width, target_value);
+ 									else if (pdesc.flags & stringfunc_PRECISION)
+ 										result = swprintf(wbuffer, len, wformat, pdesc.precision, target_value);
+ 									else
+ 										result = swprintf(wbuffer, len, wformat, target_value);
+ 									
+ 									if (result != -1)
+ 									{
+ 										/* append result */
+ 										appendStringInfo(&str, "%ls", wbuffer);
+ 										break;
+ 									}
+ 									else
+ 									{
+ 										/* increase buffer size and repeat */
+ 										len *= 2;
+ 										if ((len * sizeof(pg_wchar)) > MaxAllocSize)
+ 											ereport(ERROR,
+ 												(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+ 												 errmsg("out of memory")));
+ 												 
+ 										wbuffer = repalloc(wbuffer, len * sizeof(wchar_t) + 1);
+ 										/* continue */
+ 									}
+ 								}
+ 								
+ 								pfree(wbuffer);
+ 								pfree(wformat);
+ 							}
+ 							else
+ 							{
+ 								/* shortcut for one byte encoding */
+ 								if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 									appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 								else if (pdesc.flags & stringfunc_WIDTH)
+ 									appendStringInfo(&str, format, pdesc.width, target_value);
+ 								else if (pdesc.flags & stringfunc_PRECISION)
+ 									appendStringInfo(&str, format, pdesc.precision, target_value);
+ 								else
+ 									appendStringInfo(&str, format, target_value);
+ 								
+ 								pfree(target_value);
+ 							}
+ 						}
+ 						break;
+ 				}
+ 			}
+ 			else
+ 				/* return null when some argument is null */
+ 				PG_RETURN_NULL();
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for printf function")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 1)
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 1)
+ 			appendStringInfoString(&str, sepstr);
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Concat string with respect to SQL format. This is NULL safe.
+  * NULLs values are transformated to "NULL" string.
+  */
+ Datum
+ stringfunc_concat_sql(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData		str;
+ 	text *result;
+ 	int	i;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 0)
+ 			appendStringInfoChar(&str, ',');
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 			TYPCATEGORY	typcat;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			typcat = TypeCategory(valtype);
+ 
+ 			if (typcat == 'N' || typcat == 'B')
+ 			{
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 			{
+ 				text	*txt;
+ 				text	*quoted_txt;
+ 			
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				
+ 				/* get text value and quotize */
+ 				txt = cstring_to_text(OidOutputFunctionCall(typoutput, value));
+ 				quoted_txt = DatumGetTextP(DirectFunctionCall1(quote_literal,
+ 											    PointerGetDatum(txt)));
+ 				appendStringInfoString(&str, text_to_cstring(quoted_txt));
+ 			}
+ 		}
+ 		else
+ 			appendStringInfoString(&str, "NULL");
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ stringfunc_left(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(cstring_to_text(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, positions[n - 1] + sizes[n - 1]);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, positions[len - n - 1] + sizes[len - n - 1]);
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ stringfunc_right(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(CStringGetTextDatum(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + positions[len - n],
+ 								positions[len - 1] + sizes[len - 1] - positions[len - n]);
+ 		}
+ 		else
+ 		{
+ 			if (-n < len)
+ 			{
+ 				n = -n > len ? len : -n;
+ 				result = cstring_to_text_with_len(p + positions[n],
+ 									positions[len - 1] + sizes[len - 1] - positions[n]);
+ 			}
+ 			else
+ 			{
+ 				/* return empty string */
+ 				result = cstring_to_text_with_len("", 0);
+ 			}
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + len - n, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p + n, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ stringfunc_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text *str;
+ 	text	*result;
+ 	char	*p;
+ 	int  len;
+ 	char	*data;
+ 	int		i;
+ 
+ 	str = PG_GETARG_TEXT_PP(0);
+ 	p = VARDATA_ANY(str);
+ 	len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	data = (char*) VARDATA(result);
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		/* multibyte version */
+ 		len = mb_string_info(str, &sizes, &positions);
+ 		for (i = len - 1; i >= 0; i--)
+ 		{
+ 			memcpy(data, p + positions[i], sizes[i]);
+ 			data += sizes[i];
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		for (i = len - 1; i >= 0; i--)
+ 			*data++ = p[i];
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns length of string, size and position of every
+  * multibyte char in string.
+  */
+ static int
+ mb_string_info(text *str, char **sizes, int **positions)
+ {
+ 	int r_len;
+ 	int cur_size = 0;
+ 	int sz;
+ 	char *p;
+ 	int cur = 0;
+ 
+ 	p = VARDATA_ANY(str);
+ 	r_len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	if (NULL != sizes)
+ 		*sizes = palloc(r_len * sizeof(char));
+ 	if (NULL != positions)
+ 		*positions = palloc(r_len * sizeof(int));
+ 
+ 	while (cur < r_len)
+ 	{
+ 		sz = pg_mblen(p);
+ 		if (sizes)
+ 			(*sizes)[cur_size] = sz;
+ 		if (positions)
+ 			(*positions)[cur_size] = cur;
+ 		cur += sz;
+ 		p += sz;
+ 		cur_size += 1;
+ 	}
+ 
+ 	return cur_size;
+ }
*** ./contrib/stringfunc/stringfunc.sql.in.orig	2010-07-08 11:27:31.877299385 +0200
--- ./contrib/stringfunc/stringfunc.sql.in	2010-07-09 10:25:24.609297549 +0200
***************
*** 0 ****
--- 1,39 ----
+ CREATE OR REPLACE FUNCTION sprintf(fmt text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION sprintf(fmt text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf_nv'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat(VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_ws(separator text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_ws'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_sql(VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_sql'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION reverse(str text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_reverse'
+ LANGUAGE C IMMUTABLE STRICT;
+ 
+ CREATE OR REPLACE FUNCTION left(str text, n int)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_left'
+ LANGUAGE C IMMUTABLE STRICT;
+ 
+ CREATE OR REPLACE FUNCTION right(str text, n int)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_right'
+ LANGUAGE C IMMUTABLE STRICT;
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-03-05 15:05:47.260738126 +0100
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-07-09 10:24:17.314369259 +0200
***************
*** 0 ****
--- 1,8 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat(VARIADIC args "any");
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
+ DROP FUNCTION concat_sql(VARIADIC args "any");
+ DROP FUNCTION reverse(str text);
+ DROP FUNCTION left(str text, n int);
+ DROP FUNCTION right(str text, n int);
*** ./doc/src/sgml/contrib.sgml.orig	2010-01-29 00:59:52.000000000 +0100
--- ./doc/src/sgml/contrib.sgml	2010-03-05 15:12:18.861738045 +0100
***************
*** 113,118 ****
--- 113,119 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-02-22 12:47:30.000000000 +0100
--- ./doc/src/sgml/filelist.sgml	2010-03-09 15:04:46.210861483 +0100
***************
*** 123,128 ****
--- 123,129 ----
  <!entity pgstattuple     SYSTEM "pgstattuple.sgml">
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-03-03 23:28:42.000000000 +0100
--- ./doc/src/sgml/func.sgml	2010-03-05 14:28:25.807765920 +0100
***************
*** 1262,1267 ****
--- 1262,1270 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
***************
*** 1450,1455 ****
--- 1453,1473 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-03-05 15:11:23.284738364 +0100
--- ./doc/src/sgml/stringfunc.sgml	2010-07-09 10:55:11.569297814 +0200
***************
*** 0 ****
--- 1,73 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat(param1 [, param2 [,...]])</> a concation two or more strings
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_sql(param1 [, param2 [,...]])</> a concation two or more
+       strings. Values are converted to format of SQL constants.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>reverse(str)</> reverse a string
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>left(str, n)</> returns n chars from start. When n is negative, then 
+       returns chars without last n chars.
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>right(str, n)</> return last n chars. When n is negative, then 
+       returns chars without first n chars.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-02-26 03:01:10.000000000 +0100
--- ./src/backend/utils/adt/varlena.c	2010-07-09 10:58:52.601646871 +0200
***************
*** 3415,3417 ****
--- 3415,3504 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters for format function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				appendStringInfoString(&str, "NULL");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-02-26 03:01:21.000000000 +0100
--- ./src/include/catalog/pg_proc.h	2010-07-09 10:49:42.161422897 +0200
***************
*** 2712,2717 ****
--- 2712,2721 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-02-26 03:01:28.000000000 +0100
--- ./src/include/utils/builtins.h	2010-03-05 13:13:24.979862366 +0100
***************
*** 730,735 ****
--- 730,738 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/expected/text.out	2010-07-09 11:00:05.000000000 +0200
***************
*** 51,53 ****
--- 51,76 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters for format function
+ select format('Hello',10);
+ ERROR:  too many parameters for format function
*** ./src/test/regress/sql/text.sql.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/sql/text.sql	2010-03-05 14:09:34.083738128 +0100
***************
*** 28,30 ****
--- 28,39 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 

--- contrib/Makefile.orig	2010-07-11 00:06:30.000000000 +0200
+++ contrib/Makefile	2010-07-11 00:07:01.000000000 +0200
@@ -40,6 +40,7 @@
 		pgstattuple	\
 		seg		\
 		spi		\
+		stringfunc	\
 		tablefunc	\
 		test_parser	\
 		tsearch2	\

*** ./contrib/Makefile.orig	2009-11-18 22:57:56.000000000 +0100
--- ./contrib/Makefile	2010-07-12 10:49:24.393209559 +0200
***************
*** 37,42 ****
--- 37,43 ----
  		pgstattuple	\
  		seg		\
  		spi		\
+ 		stringfunc	\
  		tablefunc	\
  		test_parser	\
  		tsearch2	\
*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-03-09 13:28:17.082096569 +0100
--- ./contrib/stringfunc/expected/stringfunc.out	2010-07-12 22:06:56.000000000 +0200
***************
*** 0 ****
--- 1,83 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('>>>%5.2<<<', 'abcde');
+ ERROR:  unsupported sprintf format tag '<'
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+      sprintf      
+ ------------------
+  >>>    abcdef<<<
+ (1 row)
+ 
+ select sprintf('>>>%*s<<<', 10); -- error
+ ERROR:  too few parameters specified for printf function
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-03-05 15:05:20.171741922 +0100
--- ./contrib/stringfunc/Makefile	2010-03-05 14:34:31.391738508 +0100
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-03-09 13:14:14.064096132 +0100
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-07-12 22:06:21.589332311 +0200
***************
*** 0 ****
--- 1,28 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('>>>%5.2<<<', 'abcde');
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+ select sprintf('>>>%*s<<<', 10); -- error
+ select sprintf('%010d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
*** ./contrib/stringfunc/stringfunc.c.orig	2010-03-05 15:05:30.876738040 +0100
--- ./contrib/stringfunc/stringfunc.c	2010-07-12 20:48:26.896332869 +0200
***************
*** 0 ****
--- 1,609 ----
+ #include "postgres.h"
+ #include "stdio.h"
+ #include "string.h"
+ #include "wchar.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ #include "utils/memutils.h"
+ #include "utils/pg_locale.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_right(PG_FUNCTION_ARGS);
+ Datum	stringfunc_left(PG_FUNCTION_ARGS);
+ Datum	stringfunc_reverse(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ PG_FUNCTION_INFO_V1(stringfunc_reverse);
+ PG_FUNCTION_INFO_V1(stringfunc_left);
+ PG_FUNCTION_INFO_V1(stringfunc_right);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ /*
+  * Static functions
+  */
+ static int mb_string_info(text *str, char **sizes, int **positions);
+ 
+ /*
+  * External
+  */
+ extern PGDLLIMPORT char *days[];
+ 
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 						elog(NOTICE, "1");
+ 					}
+ 					else
+ 					{
+ 						bool valid = false;
+ 					
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 							valid = true;
+ 						}
+ 						
+ 						if (!valid)
+ 							ereport(ERROR,
+ 								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 								 errmsg("broken sprinf format"),
+ 								 errdetail("missing precision value")));
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprinf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 		
+ 	if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * simulate %+width.precion%s format of sprintf function 
+  */
+ static void 
+ append_string(StringInfo str,  PlaceholderDesc pdesc, char *string)
+ {
+ 	int	nchars = 0;				/* length of substring in chars */
+ 	int	binlen;				/* length of substring in bytes */
+ 
+ 	/* show only first n chars  */
+ 	if (pdesc->flags & stringfunc_PRECISION)
+ 	{
+ 		char *ptr = string;
+ 		int	  len = pdesc->precision;
+ 		
+ 		if (pg_database_encoding_max_length() > 1)
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr += pg_mblen(ptr);
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		else
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr++;
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		
+ 		binlen = ptr - string;
+ 	}
+ 	else
+ 	{
+ 		/* there isn't precion specified, show complete string */
+ 		nchars = pg_mbstrlen(string);
+ 		binlen = strlen(string);
+ 	}
+ 	
+ 	/* when width is specified, then we have to solve left or right align */
+ 	if (pdesc->flags & stringfunc_WIDTH)
+ 	{
+ 		if (pdesc->width > nchars)
+ 		{
+ 			/* add neccessary spaces to begin or end */
+ 			if (pdesc->flags & stringfunc_MINUS)
+ 			{
+ 				/* allign to left */
+ 				appendBinaryStringInfo(str, string, binlen);
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 			}
+ 			else
+ 			{
+ 				/* allign to right */
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 				appendBinaryStringInfo(str, string, binlen);
+ 			}
+ 
+ 		}
+ 		else
+ 			/* just copy result to output */
+ 			appendBinaryStringInfo(str, string, binlen);
+ 	}
+ 	else
+ 		/* just copy result to output */
+ 		appendBinaryStringInfo(str, string, binlen);
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 			
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters specified for printf function")));
+ 
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 							Oid                     typoutput;
+ 							bool            typIsVarlena;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							append_string(&str, &pdesc, target_value);
+ 							pfree(target_value);
+ 						}
+ 						break;
+ 				}
+ 			}
+ 			else
+ 				/* return null when some argument is null */
+ 				PG_RETURN_NULL();
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for printf function")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 1)
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (i > 1)
+ 			appendStringInfoString(&str, sepstr);
+ 
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
*** ./contrib/stringfunc/stringfunc.sql.in.orig	2010-07-08 11:27:31.877299385 +0200
--- ./contrib/stringfunc/stringfunc.sql.in	2010-07-12 22:08:36.012207679 +0200
***************
*** 0 ****
--- 1,14 ----
+ CREATE OR REPLACE FUNCTION sprintf(fmt text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION sprintf(fmt text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf_nv'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_ws(separator text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_ws'
+ LANGUAGE C STABLE;
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-03-05 15:05:47.260738126 +0100
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-07-12 22:05:17.990209025 +0200
***************
*** 0 ****
--- 1,3 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
*** ./doc/src/sgml/contrib.sgml.orig	2010-01-29 00:59:52.000000000 +0100
--- ./doc/src/sgml/contrib.sgml	2010-03-05 15:12:18.861738045 +0100
***************
*** 113,118 ****
--- 113,119 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-02-22 12:47:30.000000000 +0100
--- ./doc/src/sgml/filelist.sgml	2010-03-09 15:04:46.210861483 +0100
***************
*** 123,128 ****
--- 123,129 ----
  <!entity pgstattuple     SYSTEM "pgstattuple.sgml">
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-03-03 23:28:42.000000000 +0100
--- ./doc/src/sgml/func.sgml	2010-07-12 22:25:58.889336385 +0200
***************
*** 1262,1267 ****
--- 1262,1270 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
***************
*** 1372,1377 ****
--- 1375,1393 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>,
+          [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns concated strings. NULLs are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>       
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1450,1455 ****
--- 1466,1486 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
***************
*** 1462,1467 ****
--- 1493,1512 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns first n chars of string. When n is negative, then returns chars from begin
+         to n char from right.
+        </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1676,1681 ****
--- 1721,1758 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>       
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns last n chars of string. When n is negative, then returns chars from n char
+         to end of string
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>       
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-03-05 15:11:23.284738364 +0100
--- ./doc/src/sgml/stringfunc.sgml	2010-07-12 22:13:39.950213852 +0200
***************
*** 0 ****
--- 1,45 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-02-26 03:01:10.000000000 +0100
--- ./src/backend/utils/adt/varlena.c	2010-07-12 21:09:24.472333397 +0200
***************
*** 74,79 ****
--- 74,80 ----
  				bool length_not_specified);
  static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
  static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
+ static int mb_string_info(text *str, char **sizes, int **positions, int maxchars);
  
  
  /*****************************************************************************
***************
*** 3415,3417 ****
--- 3416,3757 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters for format function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				/* show same NULL string like RAISE statement */
+ 				appendStringInfoString(&str, "<NULL>");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Returns length of string, size and position of every
+  * multibyte char in string. When this function is used on 
+  * left substring, then we can get info only about first 
+  * maxchars chars.
+  */
+ static int
+ mb_string_info(text *str, char **sizes, int **positions, 
+ 							    int maxchars)
+ {
+ 	int r_len;
+ 	int cur_size = 0;
+ 	int sz;
+ 	char *p;
+ 	int cur = 0;
+ 
+ 	p = VARDATA_ANY(str);
+ 	r_len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	if (NULL != sizes)
+ 		*sizes = palloc(r_len * sizeof(char));
+ 	if (NULL != positions)
+ 		*positions = palloc(r_len * sizeof(int));
+ 
+ 	while (cur < r_len)
+ 	{
+ 		sz = pg_mblen(p);
+ 		if (sizes)
+ 			(*sizes)[cur_size] = sz;
+ 		if (positions)
+ 			(*positions)[cur_size] = cur;
+ 		cur += sz;
+ 		p += sz;
+ 		cur_size += 1;
+ 		
+ 		/* stop early when we don't need more chars */
+ 		if (maxchars != -1 && --maxchars == 0)
+ 			break;
+ 	}
+ 
+ 	return cur_size;
+ }
+ 
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(cstring_to_text(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		if (n > 0)
+ 		{
+ 			len = mb_string_info(str, &sizes, &positions, n);
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, positions[n - 1] + sizes[n - 1]);
+ 		}
+ 		else
+ 		{
+ 			len = mb_string_info(str, &sizes, &positions, -1);
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, positions[len - n - 1] + sizes[len - n - 1]);
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(CStringGetTextDatum(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions, -1);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + positions[len - n],
+ 								positions[len - 1] + sizes[len - 1] - positions[len - n]);
+ 		}
+ 		else
+ 		{
+ 			if (-n < len)
+ 			{
+ 				n = -n > len ? len : -n;
+ 				result = cstring_to_text_with_len(p + positions[n],
+ 									positions[len - 1] + sizes[len - 1] - positions[n]);
+ 			}
+ 			else
+ 			{
+ 				/* return empty string */
+ 				result = cstring_to_text_with_len("", 0);
+ 			}
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + len - n, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p + n, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text *str;
+ 	text	*result;
+ 	char	*p;
+ 	int  len;
+ 	char	*data;
+ 	int		i;
+ 
+ 	str = PG_GETARG_TEXT_PP(0);
+ 	p = VARDATA_ANY(str);
+ 	len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	data = (char*) VARDATA(result);
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		/* multibyte version */
+ 		len = mb_string_info(str, &sizes, &positions, -1);
+ 		for (i = len - 1; i >= 0; i--)
+ 		{
+ 			memcpy(data, p + positions[i], sizes[i]);
+ 			data += sizes[i];
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		for (i = len - 1; i >= 0; i--)
+ 			*data++ = p[i];
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-02-26 03:01:21.000000000 +0100
--- ./src/include/catalog/pg_proc.h	2010-07-12 22:01:17.436332903 +0200
***************
*** 2712,2717 ****
--- 2712,2729 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3094 ( concat			PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concat values to text");
+ DATA(insert OID = 3095 ( left			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("returns first n chars");
+ DATA(insert OID = 3096 ( right			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("returns last n chars");
+ DATA(insert OID = 3097 ( reverse			PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("returns reversed string");
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-02-26 03:01:28.000000000 +0100
--- ./src/include/utils/builtins.h	2010-07-12 21:07:21.301726819 +0200
***************
*** 730,735 ****
--- 730,742 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/expected/text.out	2010-07-12 22:10:17.000000000 +0200
***************
*** 51,53 ****
--- 51,154 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters for format function
+ select format('Hello',10);
+ ERROR:  too many parameters for format function
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select left('ahoj', 2);
+  left 
+ ------
+  ah
+ (1 row)
+ 
+ select left('ahoj', 5);
+  left 
+ ------
+  ahoj
+ (1 row)
+ 
+ select left('ahoj', 0);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select left('ahoj', -1);
+  left 
+ ------
+  aho
+ (1 row)
+ 
+ select left('ahoj', -10);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select right('ahoj', 2);
+  right 
+ -------
+  oj
+ (1 row)
+ 
+ select right('ahoj', 5);
+  right 
+ -------
+  ahoj
+ (1 row)
+ 
+ select right('ahoj', 0);
+  right 
+ -------
+  
+ (1 row)
+ 
+ select right('ahoj', -1);
+  right 
+ -------
+  hoj
+ (1 row)
+ 
+ select right('ahoj', -10);
+  right 
+ -------
+  
+ (1 row)
+ 
*** ./src/test/regress/sql/text.sql.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/sql/text.sql	2010-07-12 22:09:57.149208031 +0200
***************
*** 28,30 ****
--- 28,60 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ 
+ select left('ahoj', 2);
+ select left('ahoj', 5);
+ select left('ahoj', 0);
+ select left('ahoj', -1);
+ select left('ahoj', -10);
+ 
+ select right('ahoj', 2);
+ select right('ahoj', 5);
+ select right('ahoj', 0);
+ select right('ahoj', -1);
+ select right('ahoj', -10);

*** ./contrib/Makefile.orig	2009-11-18 22:57:56.000000000 +0100
--- ./contrib/Makefile	2010-07-12 10:49:24.393209559 +0200
***************
*** 37,42 ****
--- 37,43 ----
  		pgstattuple	\
  		seg		\
  		spi		\
+ 		stringfunc	\
  		tablefunc	\
  		test_parser	\
  		tsearch2	\
*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-03-09 13:28:17.082096569 +0100
--- ./contrib/stringfunc/expected/stringfunc.out	2010-07-13 09:47:40.000000000 +0200
***************
*** 0 ****
--- 1,101 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('>>>%5.2<<<', 'abcde');
+ ERROR:  unsupported sprintf format tag '<'
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+      sprintf      
+ ------------------
+  >>>    abcdef<<<
+ (1 row)
+ 
+ select sprintf('>>>%*s<<<', 10); -- error
+ ERROR:  too few parameters specified for printf function
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ select sprintf('%d', NULL);
+  sprintf 
+ ---------
+  <NULL>
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_ws(NULL,10,20,30) is null; -- yes, have to be true
+  ?column? 
+ ----------
+  t
+ (1 row)
+ 
+ select concat_ws(',',10,20,null,30);
+  concat_ws 
+ -----------
+  10,20,30
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-03-05 15:05:20.171741922 +0100
--- ./contrib/stringfunc/Makefile	2010-03-05 14:34:31.391738508 +0100
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-03-09 13:14:14.064096132 +0100
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-07-13 09:47:30.658207573 +0200
***************
*** 0 ****
--- 1,31 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('>>>%5.2<<<', 'abcde');
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+ select sprintf('>>>%*s<<<', 10); -- error
+ select sprintf('%010d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ select sprintf('%d', NULL);
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws(NULL,10,20,30) is null; -- yes, have to be true
+ select concat_ws(',',10,20,null,30);
+ 
*** ./contrib/stringfunc/stringfunc.c.orig	2010-03-05 15:05:30.876738040 +0100
--- ./contrib/stringfunc/stringfunc.c	2010-07-13 09:44:08.001207494 +0200
***************
*** 0 ****
--- 1,579 ----
+ #include "postgres.h"
+ #include "string.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 						elog(NOTICE, "1");
+ 					}
+ 					else
+ 					{
+ 						bool valid = false;
+ 					
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 							valid = true;
+ 						}
+ 						
+ 						if (!valid)
+ 							ereport(ERROR,
+ 								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 								 errmsg("broken sprintf format"),
+ 								 errdetail("missing precision value")));
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprintf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 		
+ 	if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * simulate %+width.precion%s format of sprintf function 
+  */
+ static void 
+ append_string(StringInfo str,  PlaceholderDesc pdesc, char *string)
+ {
+ 	int	nchars = 0;				/* length of substring in chars */
+ 	int	binlen;				/* length of substring in bytes */
+ 
+ 	/* show only first n chars  */
+ 	if (pdesc->flags & stringfunc_PRECISION)
+ 	{
+ 		char *ptr = string;
+ 		int	  len = pdesc->precision;
+ 		
+ 		if (pg_database_encoding_max_length() > 1)
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr += pg_mblen(ptr);
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		else
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr++;
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		
+ 		binlen = ptr - string;
+ 	}
+ 	else
+ 	{
+ 		/* there isn't precion specified, show complete string */
+ 		nchars = pg_mbstrlen(string);
+ 		binlen = strlen(string);
+ 	}
+ 	
+ 	/* when width is specified, then we have to solve left or right align */
+ 	if (pdesc->flags & stringfunc_WIDTH)
+ 	{
+ 		if (pdesc->width > nchars)
+ 		{
+ 			/* add neccessary spaces to begin or end */
+ 			if (pdesc->flags & stringfunc_MINUS)
+ 			{
+ 				/* allign to left */
+ 				appendBinaryStringInfo(str, string, binlen);
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 			}
+ 			else
+ 			{
+ 				/* allign to right */
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 				appendBinaryStringInfo(str, string, binlen);
+ 			}
+ 
+ 		}
+ 		else
+ 			/* just copy result to output */
+ 			appendBinaryStringInfo(str, string, binlen);
+ 	}
+ 	else
+ 		/* just copy result to output */
+ 		appendBinaryStringInfo(str, string, binlen);
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 			
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters specified for printf function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 							Oid                     typoutput;
+ 							bool            typIsVarlena;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							append_string(&str, &pdesc, target_value);
+ 							pfree(target_value);
+ 						}
+ 						break;
+ 				}
+ 			}
+ 			else
+ 				/* append a NULL string */
+ 				append_string(&str, &pdesc, "<NULL>");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for printf function")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	/* when separator is NULL, then return NULL */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			if (i > 1)
+ 				appendStringInfoString(&str, sepstr);
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
*** ./contrib/stringfunc/stringfunc.sql.in.orig	2010-07-08 11:27:31.877299385 +0200
--- ./contrib/stringfunc/stringfunc.sql.in	2010-07-12 22:08:36.012207679 +0200
***************
*** 0 ****
--- 1,14 ----
+ CREATE OR REPLACE FUNCTION sprintf(fmt text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION sprintf(fmt text)
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_sprintf_nv'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_ws(separator text, VARIADIC args "any")
+ RETURNS text 
+ AS 'MODULE_PATHNAME','stringfunc_concat_ws'
+ LANGUAGE C STABLE;
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-03-05 15:05:47.260738126 +0100
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-07-12 22:05:17.990209025 +0200
***************
*** 0 ****
--- 1,3 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
*** ./doc/src/sgml/contrib.sgml.orig	2010-01-29 00:59:52.000000000 +0100
--- ./doc/src/sgml/contrib.sgml	2010-03-05 15:12:18.861738045 +0100
***************
*** 113,118 ****
--- 113,119 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-02-22 12:47:30.000000000 +0100
--- ./doc/src/sgml/filelist.sgml	2010-03-09 15:04:46.210861483 +0100
***************
*** 123,128 ****
--- 123,129 ----
  <!entity pgstattuple     SYSTEM "pgstattuple.sgml">
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-03-03 23:28:42.000000000 +0100
--- ./doc/src/sgml/func.sgml	2010-07-13 09:52:22.085208093 +0200
***************
*** 1246,1251 ****
--- 1246,1254 ----
     <indexterm>
      <primary>chr</primary>
     </indexterm>
+     <indexterm>
+     <primary>concat</primary>
+    </indexterm>
     <indexterm>
      <primary>convert</primary>
     </indexterm>
***************
*** 1262,1270 ****
--- 1265,1279 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
+     <primary>left</primary>
+    </indexterm>
+    <indexterm>
      <primary>lpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1292,1297 ****
--- 1301,1312 ----
      <primary>replace</primary>
     </indexterm>
     <indexterm>
+     <primary>reverse</primary>
+    </indexterm>
+    <indexterm>
+     <primary>right</primary>
+    </indexterm>
+    <indexterm>
      <primary>rpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1372,1377 ****
--- 1387,1405 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>,
+          [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns concated strings. NULLs are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>       
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1450,1455 ****
--- 1478,1498 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
***************
*** 1462,1467 ****
--- 1505,1524 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns first n chars of string. When n is negative, then returns chars from begin
+         to n char from right.
+        </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1676,1681 ****
--- 1733,1764 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns last n chars of string. When n is negative, then returns chars from n char
+         to end of string
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-03-05 15:11:23.284738364 +0100
--- ./doc/src/sgml/stringfunc.sgml	2010-07-12 22:13:39.950213852 +0200
***************
*** 0 ****
--- 1,45 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-02-26 03:01:10.000000000 +0100
--- ./src/backend/utils/adt/varlena.c	2010-07-12 21:09:24.472333397 +0200
***************
*** 74,79 ****
--- 74,80 ----
  				bool length_not_specified);
  static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
  static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
+ static int mb_string_info(text *str, char **sizes, int **positions, int maxchars);
  
  
  /*****************************************************************************
***************
*** 3415,3417 ****
--- 3416,3757 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters for format function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				/* show same NULL string like RAISE statement */
+ 				appendStringInfoString(&str, "<NULL>");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Returns length of string, size and position of every
+  * multibyte char in string. When this function is used on 
+  * left substring, then we can get info only about first 
+  * maxchars chars.
+  */
+ static int
+ mb_string_info(text *str, char **sizes, int **positions, 
+ 							    int maxchars)
+ {
+ 	int r_len;
+ 	int cur_size = 0;
+ 	int sz;
+ 	char *p;
+ 	int cur = 0;
+ 
+ 	p = VARDATA_ANY(str);
+ 	r_len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	if (NULL != sizes)
+ 		*sizes = palloc(r_len * sizeof(char));
+ 	if (NULL != positions)
+ 		*positions = palloc(r_len * sizeof(int));
+ 
+ 	while (cur < r_len)
+ 	{
+ 		sz = pg_mblen(p);
+ 		if (sizes)
+ 			(*sizes)[cur_size] = sz;
+ 		if (positions)
+ 			(*positions)[cur_size] = cur;
+ 		cur += sz;
+ 		p += sz;
+ 		cur_size += 1;
+ 		
+ 		/* stop early when we don't need more chars */
+ 		if (maxchars != -1 && --maxchars == 0)
+ 			break;
+ 	}
+ 
+ 	return cur_size;
+ }
+ 
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(cstring_to_text(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		if (n > 0)
+ 		{
+ 			len = mb_string_info(str, &sizes, &positions, n);
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, positions[n - 1] + sizes[n - 1]);
+ 		}
+ 		else
+ 		{
+ 			len = mb_string_info(str, &sizes, &positions, -1);
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, positions[len - n - 1] + sizes[len - n - 1]);
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text *str = PG_GETARG_TEXT_PP(0);
+ 	int	len = VARSIZE_ANY_EXHDR(str);
+ 	char	*p = VARDATA_ANY(str);
+ 	text   *result;
+ 	int		n = PG_GETARG_INT32(1);
+ 	
+ 	if (len == 0 || n == 0)
+ 		PG_RETURN_TEXT_P(CStringGetTextDatum(""));
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		len = mb_string_info(str, &sizes, &positions, -1);
+ 		
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + positions[len - n],
+ 								positions[len - 1] + sizes[len - 1] - positions[len - n]);
+ 		}
+ 		else
+ 		{
+ 			if (-n < len)
+ 			{
+ 				n = -n > len ? len : -n;
+ 				result = cstring_to_text_with_len(p + positions[n],
+ 									positions[len - 1] + sizes[len - 1] - positions[n]);
+ 			}
+ 			else
+ 			{
+ 				/* return empty string */
+ 				result = cstring_to_text_with_len("", 0);
+ 			}
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		if (n > 0)
+ 		{
+ 			n = n > len ? len : n;
+ 			result = cstring_to_text_with_len(p + len - n, n);
+ 		}
+ 		else
+ 		{
+ 			n = -n > len ? len : -n;
+ 			result = cstring_to_text_with_len(p + n, len - n);
+ 		}
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text *str;
+ 	text	*result;
+ 	char	*p;
+ 	int  len;
+ 	char	*data;
+ 	int		i;
+ 
+ 	str = PG_GETARG_TEXT_PP(0);
+ 	p = VARDATA_ANY(str);
+ 	len = VARSIZE_ANY_EXHDR(str);
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	data = (char*) VARDATA(result);
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 	
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		char	*sizes;
+ 		int	*positions;
+ 		
+ 		/* multibyte version */
+ 		len = mb_string_info(str, &sizes, &positions, -1);
+ 		for (i = len - 1; i >= 0; i--)
+ 		{
+ 			memcpy(data, p + positions[i], sizes[i]);
+ 			data += sizes[i];
+ 		}
+ 		
+ 		pfree(positions);
+ 		pfree(sizes);
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		for (i = len - 1; i >= 0; i--)
+ 			*data++ = p[i];
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-02-26 03:01:21.000000000 +0100
--- ./src/include/catalog/pg_proc.h	2010-07-12 22:01:17.436332903 +0200
***************
*** 2712,2717 ****
--- 2712,2729 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3094 ( concat			PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concat values to text");
+ DATA(insert OID = 3095 ( left			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("returns first n chars");
+ DATA(insert OID = 3096 ( right			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("returns last n chars");
+ DATA(insert OID = 3097 ( reverse			PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("returns reversed string");
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-02-26 03:01:28.000000000 +0100
--- ./src/include/utils/builtins.h	2010-07-12 21:07:21.301726819 +0200
***************
*** 730,735 ****
--- 730,742 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/expected/text.out	2010-07-12 22:10:17.000000000 +0200
***************
*** 51,53 ****
--- 51,154 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters for format function
+ select format('Hello',10);
+ ERROR:  too many parameters for format function
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select left('ahoj', 2);
+  left 
+ ------
+  ah
+ (1 row)
+ 
+ select left('ahoj', 5);
+  left 
+ ------
+  ahoj
+ (1 row)
+ 
+ select left('ahoj', 0);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select left('ahoj', -1);
+  left 
+ ------
+  aho
+ (1 row)
+ 
+ select left('ahoj', -10);
+  left 
+ ------
+  
+ (1 row)
+ 
+ select right('ahoj', 2);
+  right 
+ -------
+  oj
+ (1 row)
+ 
+ select right('ahoj', 5);
+  right 
+ -------
+  ahoj
+ (1 row)
+ 
+ select right('ahoj', 0);
+  right 
+ -------
+  
+ (1 row)
+ 
+ select right('ahoj', -1);
+  right 
+ -------
+  hoj
+ (1 row)
+ 
+ select right('ahoj', -10);
+  right 
+ -------
+  
+ (1 row)
+ 
*** ./src/test/regress/sql/text.sql.orig	2007-06-07 01:00:50.000000000 +0200
--- ./src/test/regress/sql/text.sql	2010-07-12 22:09:57.149208031 +0200
***************
*** 28,30 ****
--- 28,60 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ 
+ select left('ahoj', 2);
+ select left('ahoj', 5);
+ select left('ahoj', 0);
+ select left('ahoj', -1);
+ select left('ahoj', -10);
+ 
+ select right('ahoj', 2);
+ select right('ahoj', 5);
+ select right('ahoj', 0);
+ select right('ahoj', -1);
+ select right('ahoj', -10);

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 70dab53..488e4c4 100644
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 1250,1255 ****
--- 1250,1258 ----
     <indexterm>
      <primary>chr</primary>
     </indexterm>
+     <indexterm>
+     <primary>concat</primary>
+    </indexterm>
     <indexterm>
      <primary>convert</primary>
     </indexterm>
***************
*** 1266,1274 ****
--- 1269,1283 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
+     <primary>left</primary>
+    </indexterm>
+    <indexterm>
      <primary>lpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1296,1301 ****
--- 1305,1316 ----
      <primary>replace</primary>
     </indexterm>
     <indexterm>
+     <primary>reverse</primary>
+    </indexterm>
+    <indexterm>
+     <primary>right</primary>
+    </indexterm>
+    <indexterm>
      <primary>rpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1376,1381 ****
--- 1391,1409 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>,
+          [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns concated strings. NULLs are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1454,1459 ****
--- 1482,1502 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
***************
*** 1466,1471 ****
--- 1509,1528 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns first n chars of string. When n is negative, then returns chars from begin
+         to n char from right.
+        </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1680,1685 ****
--- 1737,1768 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns last n chars of string. When n is negative, then returns chars from n char
+         to end of string
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index af28c15..e62cf6e 100644
*** a/src/backend/utils/adt/varlena.c
--- b/src/backend/utils/adt/varlena.c
*************** string_agg_finalfn(PG_FUNCTION_ARGS)
*** 3415,3417 ****
--- 3415,3635 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Replaces % symbols with the external representation of the arguments.
+  *
+  * Syntax: text_format(format text [, arg "any"] ...) RETURNS text
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text		   *fmt;
+ 	size_t			len;
+ 	StringInfoData	str;
+ 	const char	   *cp,
+ 				   *start_ptr,
+ 				   *end_ptr;
+ 	int				n;
+ 	text		   *result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 	initStringInfo(&str);
+ 
+ 	n = 1;
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		/*
+ 		 * Occurrences of a single % are replaced by the next parameter's
+ 		 * external representation. Double %'s are converted to one %.
+ 		 */
+ 		if (cp[0] != '%')
+ 		{
+ 			appendStringInfoChar(&str, cp[0]);
+ 		}
+ 		else if (cp < end_ptr && cp[1] == '%')
+ 		{
+ 			appendStringInfoChar(&str, '%');
+ 			cp++;
+ 		}
+ 		else if (n >= PG_NARGS())
+ 		{
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters for format function")));
+ 		}
+ 		else
+ 		{
+ 			if (PG_ARGISNULL(n))
+ 			{
+ 				/* A NULL value is shown as '<NULL>'. */
+ 				appendStringInfoString(&str, "<NULL>");
+ 			}
+ 			else
+ 			{
+ 				Datum	value;
+ 				Oid		type;
+ 				Oid		typOutput;
+ 				bool	typIsVarlena;
+ 
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(n);
+ 				type = get_fn_expr_argtype(fcinfo->flinfo, n);
+ 				getTypeOutputInfo(type, &typOutput, &typIsVarlena);
+ 				appendStringInfoString(&str,
+ 					OidOutputFunctionCall(typOutput, value));
+ 			}
+ 			n++;
+ 		}
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (n != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non-variadic version of text_format only to validate format string.
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
+ 
+ /*
+  * Concatenates arguments. NULL values are skipped.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData	str;
+ 	int				i;
+ 	text		   *result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 
+ 	for (i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Datum	value;
+ 			Oid		type;
+ 			Oid		typOutput;
+ 			bool	typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			type = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			getTypeOutputInfo(type, &typOutput, &typIsVarlena);
+ 			appendStringInfoString(&str,
+ 				OidOutputFunctionCall(typOutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ 
+ /*
+  * Returns first n characters. When n is negative, returns chars without
+  * last |n| characters.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			rlen;
+ 
+ 	if (n < 0)
+ 		n = pg_mbstrlen_with_len(p, len) + n;
+ 	rlen = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+ }
+ 
+ /*
+  * Returns last n characters. When n is negative, returns string without
+  * first |n| characters.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			off;
+ 
+ 	if (n < 0)
+ 		n = -n;
+ 	else
+ 		n = pg_mbstrlen_with_len(p, len) - n;
+ 	off = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text		   *str = PG_GETARG_TEXT_PP(0);
+ 	const char	   *p = VARDATA_ANY(str);
+ 	int				len = VARSIZE_ANY_EXHDR(str);
+ 	const char	   *endp = p + len;
+ 	text		   *result;
+ 	char		   *dst;
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	dst = (char*) VARDATA(result) + len;
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		/* multibyte version */
+ 		while (p < endp)
+ 		{
+ 			int		sz;
+ 
+ 			sz = pg_mblen(p);
+ 			dst -= sz;
+ 			memcpy(dst, p, sz);
+ 			p += sz;
+ 		}
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		while (p < endp)
+ 			*(--dst) = *p++;
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 6036493..87c891d 100644
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
*************** DESCR("I/O");
*** 2718,2723 ****
--- 2718,2735 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3094 ( concat			PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concat values to text");
+ DATA(insert OID = 3095 ( left			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("returns first n chars");
+ DATA(insert OID = 3096 ( right			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("returns last n chars");
+ DATA(insert OID = 3097 ( reverse			PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("returns reversed string");
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 45123fd..5c4cd44 100644
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
*************** extern Datum string_agg_transfn(PG_FUNCT
*** 731,736 ****
--- 731,743 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
diff --git a/src/test/regress/expected/text.out b/src/test/regress/expected/text.out
index 08d002f..f561d61 100644
*** a/src/test/regress/expected/text.out
--- b/src/test/regress/expected/text.out
*************** ERROR:  operator does not exist: integer
*** 51,53 ****
--- 51,126 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters for format function
+ select format('Hello',10);
+ ERROR:  too many parameters for format function
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select i, left('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+  i  | left 
+ ----+------
+  -5 | 
+  -4 | 
+  -3 | a
+  -2 | ah
+  -1 | aho
+   0 | 
+   1 | a
+   2 | ah
+   3 | aho
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
+ select i, right('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+  i  | right 
+ ----+-------
+  -5 | 
+  -4 | 
+  -3 | j
+  -2 | oj
+  -1 | hoj
+   0 | 
+   1 | j
+   2 | oj
+   3 | hoj
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
diff --git a/src/test/regress/sql/text.sql b/src/test/regress/sql/text.sql
index b739e56..e22f18b 100644
*** a/src/test/regress/sql/text.sql
--- b/src/test/regress/sql/text.sql
*************** select 'four: ' || 2+2;
*** 28,30 ****
--- 28,50 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ select i, left('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+ select i, right('ahoj', i) from generate_series(-5, 5) t(i) order by i;

*** ./contrib/Makefile.orig	2010-06-14 18:17:56.000000000 +0200
--- ./contrib/Makefile	2010-07-24 08:35:36.983179050 +0200
***************
*** 40,45 ****
--- 40,46 ----
  		pgstattuple	\
  		seg		\
  		spi		\
+ 		stringfunc	\
  		tablefunc	\
  		test_parser	\
  		tsearch2	\
*** ./contrib/stringfunc/expected/stringfunc.out.orig	2010-07-24 08:35:11.716063627 +0200
--- ./contrib/stringfunc/expected/stringfunc.out	2010-07-24 17:09:34.000000000 +0200
***************
*** 0 ****
--- 1,140 ----
+ SET client_min_messages = warning;
+ \set ECHO none
+ RESET client_min_messages;
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+            sprintf           
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select sprintf('>>>%-10s<<<', 'hello');
+      sprintf      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select sprintf('>>>%5.2<<<', 'abcde');
+ ERROR:  unsupported sprintf format tag '<'
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+      sprintf      
+ ------------------
+  >>>    abcdef<<<
+ (1 row)
+ 
+ select sprintf('>>>%*s<<<', 10); -- error
+ ERROR:  too few parameters specified for printf function
+ select sprintf('%010d', 10);
+   sprintf   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select sprintf('%.6d', 10);
+  sprintf 
+ ---------
+  000010
+ (1 row)
+ 
+ select sprintf('%d', 100.0/3.0);
+  sprintf 
+ ---------
+  33
+ (1 row)
+ 
+ select sprintf('%e', 100.0/3.0);
+    sprintf    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select sprintf('%f', 100.0/3.0);
+   sprintf  
+ -----------
+  33.333333
+ (1 row)
+ 
+ select sprintf('%g', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4e', 100.0/3.0);
+   sprintf   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select sprintf('%7.4f', 100.0/3.0);
+  sprintf 
+ ---------
+  33.3333
+ (1 row)
+ 
+ select sprintf('%7.4g', 100.0/3.0);
+  sprintf 
+ ---------
+    33.33
+ (1 row)
+ 
+ select sprintf('%d', NULL);
+  sprintf 
+ ---------
+  <NULL>
+ (1 row)
+ 
+ select sprintf('some identifier: %iq', 'tab');
+        sprintf        
+ ----------------------
+  some identifier: tab
+ (1 row)
+ 
+ select sprintf('some identifier: %iq', 'my tab');
+           sprintf          
+ ---------------------------
+  some identifier: "my tab"
+ (1 row)
+ 
+ select sprintf('some identifier: %iq', NULL); -- should fail
+ ERROR:  null value not allowed
+ HINT:  cannot to use NULL as identifier
+ select sprintf('some literal: %lq', 'yellow dog');
+           sprintf           
+ ----------------------------
+  some literal: 'yellow dog'
+ (1 row)
+ 
+ select sprintf('some literal: %lq', e'yellow \' dog');
+             sprintf            
+ -------------------------------
+  some literal: 'yellow '' dog'
+ (1 row)
+ 
+ select sprintf('some literal: %lq', NULL);
+       sprintf       
+ --------------------
+  some literal: NULL
+ (1 row)
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_ws(NULL,10,20,30) is null; -- yes, have to be true
+  ?column? 
+ ----------
+  t
+ (1 row)
+ 
+ select concat_ws(',',10,20,null,30);
+  concat_ws 
+ -----------
+  10,20,30
+ (1 row)
+ 
*** ./contrib/stringfunc/Makefile.orig	2010-07-24 08:34:20.228063356 +0200
--- ./contrib/stringfunc/Makefile	2010-07-24 08:35:36.984064643 +0200
***************
*** 0 ****
--- 1,17 ----
+ # $PostgreSQL: pgsql/contrib/stringfunc/Makefile,v 1.1 2008/07/29 18:31:20 tgl Exp $
+ 
+ MODULES = stringfunc
+ DATA_built = stringfunc.sql
+ DATA = uninstall_stringfunc.sql
+ REGRESS = stringfunc
+ 
+ ifdef USE_PGXS
+ PG_CONFIG = pg_config
+ PGXS := $(shell $(PG_CONFIG) --pgxs)
+ include $(PGXS)
+ else
+ subdir = contrib/stringfunc
+ top_builddir = ../..
+ include $(top_builddir)/src/Makefile.global
+ include $(top_srcdir)/contrib/contrib-global.mk
+ endif
*** ./contrib/stringfunc/sql/stringfunc.sql.orig	2010-07-24 08:34:20.230063344 +0200
--- ./contrib/stringfunc/sql/stringfunc.sql	2010-07-24 17:09:18.615359594 +0200
***************
*** 0 ****
--- 1,40 ----
+ 
+ SET client_min_messages = warning;
+ \set ECHO none
+ \i stringfunc.sql
+ \set ECHO all
+ RESET client_min_messages;
+ 
+ -- sprintf test
+ select sprintf('>>>%10s %10d<<<', 'hello', 10);
+ select sprintf('>>>%-10s<<<', 'hello');
+ select sprintf('>>>%5.2<<<', 'abcde');
+ select sprintf('>>>%*s<<<', 10, 'abcdef');
+ select sprintf('>>>%*s<<<', 10); -- error
+ select sprintf('%010d', 10);
+ select sprintf('%.6d', 10);
+ 
+ select sprintf('%d', 100.0/3.0);
+ select sprintf('%e', 100.0/3.0);
+ select sprintf('%f', 100.0/3.0);
+ select sprintf('%g', 100.0/3.0);
+ select sprintf('%7.4e', 100.0/3.0);
+ select sprintf('%7.4f', 100.0/3.0);
+ select sprintf('%7.4g', 100.0/3.0);
+ select sprintf('%d', NULL);
+ 
+ select sprintf('some identifier: %iq', 'tab');
+ select sprintf('some identifier: %iq', 'my tab');
+ select sprintf('some identifier: %iq', NULL); -- should fail
+ 
+ select sprintf('some literal: %lq', 'yellow dog');
+ select sprintf('some literal: %lq', e'yellow \' dog');
+ select sprintf('some literal: %lq', NULL);
+ 
+ /*
+  * concat tests
+  */
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws(NULL,10,20,30) is null; -- yes, have to be true
+ select concat_ws(',',10,20,null,30);
+ 
*** ./contrib/stringfunc/stringfunc.c.orig	2010-07-24 08:34:20.231063477 +0200
--- ./contrib/stringfunc/stringfunc.c	2010-07-24 16:50:53.393361802 +0200
***************
*** 0 ****
--- 1,658 ----
+ #include "postgres.h"
+ #include "string.h"
+ 
+ #include "catalog/pg_type.h"
+ #include "lib/stringinfo.h"
+ #include "mb/pg_wchar.h"
+ #include "parser/parse_coerce.h"
+ #include "utils/builtins.h"
+ #include "utils/lsyscache.h"
+ 
+ PG_MODULE_MAGIC;
+ 
+ #define CHECK_PAD(symbol, pad_value)	\
+ do { \
+ 	if (pdesc->flags & pad_value)		\
+ 		ereport(ERROR,  	\
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("broken sprintf format"),          \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), 	   \
+ 				 errhint("Symbol '%c' can be used only one time.", symbol))); \
+ 	pdesc->flags |= pad_value; \
+ } while(0);
+ 
+ /*
+  * string functions
+  */
+ Datum	stringfunc_sprintf(PG_FUNCTION_ARGS);
+ Datum	stringfunc_sprintf_nv(PG_FUNCTION_ARGS);
+ Datum	stringfunc_concat_ws(PG_FUNCTION_ARGS);
+ 
+ /*
+  * V1 registrations
+  */
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf);
+ PG_FUNCTION_INFO_V1(stringfunc_sprintf_nv);
+ PG_FUNCTION_INFO_V1(stringfunc_concat_ws);
+ 
+ typedef enum {
+     stringfunc_ZERO       =   1,
+     stringfunc_SPACE      =   2,
+     stringfunc_PLUS       =   4,
+     stringfunc_MINUS      =   8,
+     stringfunc_STAR_WIDTH =  16,
+     stringfunc_SHARP      =  32,
+     stringfunc_WIDTH      =  64,
+     stringfunc_PRECISION  = 128,
+     stringfunc_STAR_PRECISION = 256
+ } PlaceholderTags;
+ 
+ typedef struct {
+ 	int	flags;
+ 	char		field_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ 	char		quoting_type;
+ } FormatPlaceholderData;
+ 
+ typedef FormatPlaceholderData *PlaceholderDesc;
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid		funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo	finfo;
+ 	Datum	   result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typoutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typoutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typoutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ /*
+  * parse and verify sprintf parameter 
+  *
+  *      %[flags][width][.precision]specifier
+  *
+  */
+ static char *
+ parsePlaceholder(char *src, char *end_ptr, PlaceholderDesc pdesc, text *fmt)
+ {
+ 	char		c;
+ 
+ 	pdesc->field_type = '\0';
+ 	pdesc->lenmod = '\0';
+ 	pdesc->flags = 0;
+ 	pdesc->width = 0;
+ 	pdesc->precision = 0;
+ 	pdesc->quoting_type = '\0';
+ 
+ 	while (src < end_ptr && pdesc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 		
+ 		/*
+ 		 * sprintf supports the most common formats that has a sense for high level
+ 		 * programming language with two additions - format tags "iq" and "lq". 
+ 		 * These tags can be used in sense "identifier qouted" and "literal quoted".
+ 		 */
+ 		if (c == 'i' || c == 'l')
+ 		{
+ 			/* look forward - can be a proprietary tag */
+ 			if (src < end_ptr && src[1] == 'q')
+ 			{
+ 				pdesc->field_type = *++src;
+ 				pdesc->quoting_type = c;
+ 
+ 				continue;
+ 			}
+ 		}
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', stringfunc_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', stringfunc_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', stringfunc_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', stringfunc_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', stringfunc_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', stringfunc_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': 
+ 				pdesc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', stringfunc_WIDTH);
+ 				pdesc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					pdesc->width = pdesc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', stringfunc_STAR_PRECISION);
+ 						src++;
+ 					}
+ 					else
+ 					{
+ 						/*
+ 						 * when no one digit is entered, then precision
+ 						 * is zero - digits are optional.
+ 						 */
+ 						CHECK_PAD('.', stringfunc_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 						{
+ 							pdesc->precision = pdesc->precision * 10 + *++src - '0';
+ 						}
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("broken sprintf format"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported sprintf format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (pdesc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format")));
+ 
+ 	return src;
+ }
+ 
+ static char *
+ currentFormat(StringInfo str, PlaceholderDesc pdesc)
+ {
+ 	resetStringInfo(str);
+ 	appendStringInfoChar(str,'%');
+ 	
+ 	if (pdesc->flags & stringfunc_ZERO)
+ 		appendStringInfoChar(str, '0');
+ 
+ 	if (pdesc->flags & stringfunc_MINUS)
+ 		appendStringInfoChar(str, '-');
+ 
+ 	if (pdesc->flags & stringfunc_PLUS)
+ 		appendStringInfoChar(str, '+');
+ 		
+ 	if (pdesc->flags & stringfunc_SPACE)
+ 		appendStringInfoChar(str, ' ');
+ 		
+ 	if (pdesc->flags & stringfunc_SHARP)
+ 		appendStringInfoChar(str, '#');
+ 
+ 	if ((pdesc->flags & stringfunc_WIDTH) || (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		appendStringInfoChar(str, '*');
+ 		
+ 	if ((pdesc->flags & stringfunc_PRECISION) || (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		appendStringInfoString(str, ".*");
+ 
+ 	/* Append l or ll. Decision is based on value of INT64_FORMAT */
+ 	if (pdesc->lenmod == 'l')
+ 	{
+ 		if (strcmp(INT64_FORMAT, "%lld") == 0)
+ 			appendStringInfoString(str, "ll");
+ 		else
+ 			appendStringInfoString(str, "l");
+ 	}
+ 	else if (pdesc->lenmod != '\0')
+ 		appendStringInfoChar(str, pdesc->lenmod);
+ 
+ 	appendStringInfoChar(str, pdesc->field_type);
+ 	
+ 	return str->data;
+ }
+ 
+ /*
+  * simulate %+width.precion%s format of sprintf function 
+  */
+ static void 
+ append_string(StringInfo str,  PlaceholderDesc pdesc, char *string)
+ {
+ 	int	nchars = 0;				/* length of substring in chars */
+ 	int	binlen = 0;				/* length of substring in bytes */
+ 
+ 	/*
+ 	 * apply precision - it means "show only first n chars", for strings - this flag is 
+ 	 * ignored for proprietary tags %lq and iq, because we can't to show a first n chars 
+ 	 * from possible quoted value. 
+ 	 */
+ 	if (pdesc->flags & stringfunc_PRECISION && pdesc->field_type != 'q')
+ 	{
+ 		char *ptr = string;
+ 		int	  len = pdesc->precision;
+ 		
+ 		if (pg_database_encoding_max_length() > 1)
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr += pg_mblen(ptr);
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		else
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr++;
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		
+ 		binlen = ptr - string;
+ 	}
+ 	else
+ 	{
+ 		/* there isn't precion specified, show complete string */
+ 		nchars = pg_mbstrlen(string);
+ 		binlen = strlen(string);
+ 	}
+ 	
+ 	/* when width is specified, then we have to solve left or right align */
+ 	if (pdesc->flags & stringfunc_WIDTH)
+ 	{
+ 		if (pdesc->width > nchars)
+ 		{
+ 			/* add neccessary spaces to begin or end */
+ 			if (pdesc->flags & stringfunc_MINUS)
+ 			{
+ 				/* allign to left */
+ 				appendBinaryStringInfo(str, string, binlen);
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 			}
+ 			else
+ 			{
+ 				/* allign to right */
+ 				appendStringInfoSpaces(str, pdesc->width - nchars);
+ 				appendBinaryStringInfo(str, string, binlen);
+ 			}
+ 
+ 		}
+ 		else
+ 			/* just copy result to output */
+ 			appendBinaryStringInfo(str, string, binlen);
+ 	}
+ 	else
+ 		/* just copy result to output */
+ 		appendBinaryStringInfo(str, string, binlen);
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static 
+ int setWidthAndPrecision(PlaceholderDesc pdesc, FunctionCallInfoData *fcinfo, int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((pdesc->flags & stringfunc_WIDTH) && (pdesc->flags & stringfunc_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((pdesc->flags & stringfunc_PRECISION) && (pdesc->flags & stringfunc_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("broken sprintf format"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (pdesc->flags & stringfunc_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		pdesc->flags ^= stringfunc_STAR_WIDTH;
+ 		pdesc->flags |= stringfunc_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (pdesc->flags & stringfunc_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters specified for printf function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		pdesc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		pdesc->flags ^= stringfunc_STAR_PRECISION;
+ 		pdesc->flags |= stringfunc_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * sprintf function - it is wrapper for libc vprintf function
+  *
+  *    ensure PostgreSQL -> C casting
+  */
+ Datum
+ stringfunc_sprintf(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData   str;
+ 	StringInfoData   format_str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	FormatPlaceholderData		pdesc;
+ 	text *result;
+ 
+ 	Oid                     typoutput;
+ 	bool            typIsVarlena;
+ 	Datum 	value;
+ 	Oid valtype;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	initStringInfo(&format_str);
+ 
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			cp = parsePlaceholder(cp, end_ptr, &pdesc, fmt);
+ 			i = setWidthAndPrecision(&pdesc, fcinfo, i);
+ 			
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters specified for printf function")));
+ 
+ 			/*
+ 			 * Proprietary tags %iq and %lq needs a call of adequate quoting function.
+ 			 * For tag %lq is special handling of NULL - similar to quote_nullable.
+ 			 * NULL cannot be used as identifier - so exception is raised when tag 
+ 			 * is %iq. 
+ 			 */
+ 			if (pdesc.field_type == 'q')
+ 			{
+ 				if (!PG_ARGISNULL(i))
+ 				{
+ 					char	*target_value;
+ 
+ 					value = PG_GETARG_DATUM(i);
+ 					valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 					getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 					target_value = OidOutputFunctionCall(typoutput, value);
+ 					
+ 					if (pdesc.quoting_type == 'l')
+ 					{
+ 						text	*txt;
+ 						text	*quoted_txt;
+ 						char	*quoted_str;
+ 						
+ 						txt = cstring_to_text(target_value);
+ 						quoted_txt = DatumGetTextP(DirectFunctionCall1(quote_literal, PointerGetDatum(txt)));
+ 						quoted_str = text_to_cstring(quoted_txt);
+ 						append_string(&str, &pdesc, quoted_str);
+ 						
+ 						pfree(quoted_str);
+ 					}
+ 					else
+ 					{
+ 						const char *quoted_str;
+ 						
+ 						quoted_str = quote_identifier(target_value);
+ 						append_string(&str, &pdesc, (char *) quoted_str);
+ 					}
+ 						
+ 					pfree(target_value);
+ 				}
+ 				else
+ 				{
+ 					if (pdesc.quoting_type == 'i')
+ 						ereport(ERROR,
+ 							    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 							     errmsg("null value not allowed"),
+ 							     errhint("cannot to use NULL as identifier")));
+ 							
+ 					append_string(&str, &pdesc, "NULL");
+ 				}
+ 			}
+ 			else if (!PG_ARGISNULL(i))
+ 		        {
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 				
+ 				/* convert value to target type */
+ 				switch (pdesc.field_type)
+ 				{
+ 					case 'o': case 'd': case 'i': case 'x': case 'X':
+ 						{
+ 							int64	target_value;
+ 							const char 		*format;
+ 							
+ 							pdesc.lenmod = 'l';
+ 							target_value = DatumGetInt64(castValueTo(value, INT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 'e': case 'f': case 'g': case 'G': case 'E':
+ 						{
+ 							float8	target_value;
+ 							const char 		*format;
+ 							
+ 							target_value = DatumGetFloat8(castValueTo(value, FLOAT8OID, valtype));
+ 							format = currentFormat(&format_str, &pdesc);
+ 							
+ 							if ((pdesc.flags & stringfunc_WIDTH) && (pdesc.flags & stringfunc_PRECISION))
+ 								appendStringInfo(&str, format, pdesc.width, pdesc.precision, target_value);
+ 							else if (pdesc.flags & stringfunc_WIDTH)
+ 								appendStringInfo(&str, format, pdesc.width, target_value);
+ 							else if (pdesc.flags & stringfunc_PRECISION)
+ 								appendStringInfo(&str, format, pdesc.precision, target_value);
+ 							else
+ 								appendStringInfo(&str, format, target_value);
+ 						}
+ 						break;
+ 					case 's':
+ 						{
+ 							char		*target_value;
+ 
+ 							getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 							target_value = OidOutputFunctionCall(typoutput, value);
+ 							
+ 							append_string(&str, &pdesc, target_value);
+ 							pfree(target_value);
+ 						}
+ 						break;
+ 					default:
+ 						elog(ERROR, "unknown format: %c", pdesc.field_type);
+ 				}
+ 			}
+ 			else
+ 				/* append a NULL string */
+ 				append_string(&str, &pdesc, "<NULL>");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for printf function")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	
+ 	pfree(str.data);
+ 	pfree(format_str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * only wrapper
+  */
+ Datum
+ stringfunc_sprintf_nv(PG_FUNCTION_ARGS)
+ {
+ 	return stringfunc_sprintf(fcinfo);
+ }
+ 
+ /*
+  * Concat values. First argument is separator. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ stringfunc_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	text *result;
+ 	char	*sepstr;
+ 	int	i;
+ 	
+ 	/* when separator is NULL, then return NULL */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	sepstr = text_to_cstring(PG_GETARG_TEXT_P(0));
+ 	initStringInfo(&str);
+ 
+ 	for(i = 1; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			if (i > 1)
+ 				appendStringInfoString(&str, sepstr);
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
*** ./contrib/stringfunc/stringfunc.sql.orig	2010-07-24 08:34:20.233062905 +0200
--- ./contrib/stringfunc/stringfunc.sql	2010-07-24 09:41:27.224063513 +0200
***************
*** 0 ****
--- 1,14 ----
+ CREATE OR REPLACE FUNCTION sprintf(fmt text, VARIADIC args "any")
+ RETURNS text 
+ AS '$libdir/stringfunc','stringfunc_sprintf'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION sprintf(fmt text)
+ RETURNS text 
+ AS '$libdir/stringfunc','stringfunc_sprintf_nv'
+ LANGUAGE C STABLE;
+ 
+ CREATE OR REPLACE FUNCTION concat_ws(separator text, VARIADIC args "any")
+ RETURNS text 
+ AS '$libdir/stringfunc','stringfunc_concat_ws'
+ LANGUAGE C STABLE;
*** ./contrib/stringfunc/uninstall_stringfunc.sql.orig	2010-07-24 08:34:20.234063319 +0200
--- ./contrib/stringfunc/uninstall_stringfunc.sql	2010-07-24 08:35:36.987062529 +0200
***************
*** 0 ****
--- 1,3 ----
+ DROP FUNCTION sprintf(fmt text, VARIADIC args "any");
+ DROP FUNCTION sprintf(fmt text);
+ DROP FUNCTION concat_ws(separator text, VARIADIC args "any");
*** ./doc/src/sgml/contrib.sgml.orig	2010-06-14 19:25:24.000000000 +0200
--- ./doc/src/sgml/contrib.sgml	2010-07-24 08:35:36.987062529 +0200
***************
*** 115,120 ****
--- 115,121 ----
   &seg;
   &contrib-spi;
   &sslinfo;
+  &stringfunc;
   &tablefunc;
   &test-parser;
   &tsearch2;
*** ./doc/src/sgml/filelist.sgml.orig	2010-06-14 19:25:24.000000000 +0200
--- ./doc/src/sgml/filelist.sgml	2010-07-24 08:35:36.989062796 +0200
***************
*** 125,130 ****
--- 125,131 ----
  <!entity pgtrgm          SYSTEM "pgtrgm.sgml">
  <!entity pgupgrade       SYSTEM "pgupgrade.sgml">
  <!entity seg             SYSTEM "seg.sgml">
+ <!entity stringfunc      SYSTEM "stringfunc.sgml">
  <!entity contrib-spi     SYSTEM "contrib-spi.sgml">
  <!entity sslinfo         SYSTEM "sslinfo.sgml">
  <!entity tablefunc       SYSTEM "tablefunc.sgml">
*** ./doc/src/sgml/func.sgml.orig	2010-07-03 19:21:48.000000000 +0200
--- ./doc/src/sgml/func.sgml	2010-07-24 08:35:37.001070823 +0200
***************
*** 1250,1255 ****
--- 1250,1258 ----
     <indexterm>
      <primary>chr</primary>
     </indexterm>
+     <indexterm>
+     <primary>concat</primary>
+    </indexterm>
     <indexterm>
      <primary>convert</primary>
     </indexterm>
***************
*** 1266,1274 ****
--- 1269,1283 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
+     <primary>left</primary>
+    </indexterm>
+    <indexterm>
      <primary>lpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1296,1301 ****
--- 1305,1316 ----
      <primary>replace</primary>
     </indexterm>
     <indexterm>
+     <primary>reverse</primary>
+    </indexterm>
+    <indexterm>
+     <primary>right</primary>
+    </indexterm>
+    <indexterm>
      <primary>rpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1376,1381 ****
--- 1391,1409 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>,
+          [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns concated strings. NULLs are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>       
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1454,1459 ****
--- 1482,1502 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         The format string can be followed by optional argument values to be inserted into 
+         the result string. Inside the format string, % is replaced by the string representation 
+         of the next optional argument's value. Write %% to emit a literal %.
+        </entry>
+        <entry><literal>format('% % xxx: %', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>       
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
***************
*** 1466,1471 ****
--- 1509,1528 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns first n chars of string. When n is negative, then returns chars from begin
+         to n char from right.
+        </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1680,1685 ****
--- 1737,1768 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns last n chars of string. When n is negative, then returns chars from n char
+         to end of string
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
*** ./doc/src/sgml/stringfunc.sgml.orig	2010-07-24 08:35:11.720062485 +0200
--- ./doc/src/sgml/stringfunc.sgml	2010-07-24 17:05:58.474380848 +0200
***************
*** 0 ****
--- 1,47 ----
+ <!-- $PostgreSQL: pgsql/doc/src/sgml/stringfunc.sgml,v 1.2 2008/09/12 18:29:49 tgl Exp $ -->
+ 
+ <sect1 id="stringfunc">
+  <title>stringfunc</title>
+ 
+  <indexterm zone="stringfunc">
+   <primary>stringfunc</primary>
+  </indexterm>
+ 
+  <para>
+   The <filename>stringfunc</> module provides a additional function
+   for operation over strings. These functions can be used as patter
+   for developing a variadic functions.
+  </para>
+ 
+  <sect2>
+   <title>How to Use It</title>
+ 
+   <para>
+    Here's a simple example of usage:
+ 
+   <programlisting>
+    SELECT sprintf('formated number: %10d',10);
+   </programlisting>
+   </para>
+ 
+   <para>
+    Nodul contains following functions:
+   </para>
+ 
+   <itemizedlist>
+    <listitem>
+     <para>
+       <function>sprintf(formatstr [, params])</> clasic sprintf function - it 
+       simplyfied version of libc sprintf function - it doesn't support length
+       modifiers and it will do necessary conversions automaticaly.  
+     </para>
+    </listitem>
+    <listitem>
+     <para>
+       <function>concat_ws(separator, param1 [, param2 [,...]])()</> a concation two 
+       or more strings. First parameter is used as separator.
+     </para>
+    </listitem>
+   </itemizedlist>
+  </sect2>
+ </sect1>
*** ./src/backend/utils/adt/varlena.c.orig	2010-07-24 08:31:50.617103415 +0200
--- ./src/backend/utils/adt/varlena.c	2010-07-24 08:53:52.567065985 +0200
***************
*** 74,79 ****
--- 74,80 ----
  				bool length_not_specified);
  static bytea *bytea_overlay(bytea *t1, bytea *t2, int sp, int sl);
  static StringInfo makeStringAggState(FunctionCallInfo fcinfo);
+ static int mb_string_info(text *str, char **sizes, int **positions, int maxchars);
  
  
  /*****************************************************************************
***************
*** 3415,3417 ****
--- 3416,3629 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ /*
+  * Text format - a variadic function replaces % symbols with entered text.
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text	   *fmt;
+ 	StringInfoData		str;
+ 	char		*cp;
+ 	int			i = 1;
+ 	size_t		len;
+ 	char		*start_ptr,
+ 				*end_ptr;
+ 	text	*result;
+ 
+ 	/* When format string is null, returns null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	len = VARSIZE_ANY_EXHDR(fmt);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + len - 1;
+ 
+ 	initStringInfo(&str);
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		if (cp[0] == '%')
+ 		{
+ 
+ 			/* when cp is not pointer on last char, check %% */
+ 			if (cp < end_ptr && cp[1] == '%')
+ 			{
+ 				appendStringInfoChar(&str, cp[1]);
+ 				cp++;
+ 				continue;
+ 			}
+ 
+ 			if (i >= PG_NARGS())
+ 				ereport(ERROR,
+ 						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 						 errmsg("too few parameters for format function")));
+ 
+ 			if (!PG_ARGISNULL(i))
+ 		        {
+ 				Oid	valtype;
+ 				Datum	value;
+ 				Oid                     typoutput;
+ 				bool            typIsVarlena;
+ 		        
+ 				/* append n-th value */
+ 				value = PG_GETARG_DATUM(i);
+ 				valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 				getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 				appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 			}
+ 			else
+ 				/* show same NULL string like RAISE statement */
+ 				appendStringInfoString(&str, "<NULL>");
+ 			i++;
+ 		}
+ 		else
+ 			appendStringInfoChar(&str, cp[0]);
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (i != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+         PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non variadic text_format function - only wrapper
+  *   Print and check format string
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
+ 
+ /*
+  * Concat values to comma separated list. This function
+  * is NULL safe. NULL values are skipped.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	StringInfoData   str;
+ 	int	i;
+ 	text	*result;
+ 
+ 	/* return NULL, if there are not any parameter */
+ 	if (PG_NARGS() == 0)
+ 		PG_RETURN_NULL();
+ 
+ 	initStringInfo(&str);
+ 	
+ 	for(i = 0; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid	valtype;
+ 			Datum	value;
+ 			Oid                     typoutput;
+ 			bool            typIsVarlena;
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 
+ 			getTypeOutputInfo(valtype, &typoutput, &typIsVarlena);
+ 			appendStringInfoString(&str, OidOutputFunctionCall(typoutput, value));
+ 		}
+ 	}
+ 	
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Returns first n chars. When n is negative, then
+  * it returns chars from n+1 position.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			rlen;
+ 
+ 	if (n < 0)
+ 		n = pg_mbstrlen_with_len(p, len) + n;
+ 	rlen = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+ }
+ 
+ /*
+  * Returns last n chars from string. When n is negative,
+  * then returns string without last n chars.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			off;
+ 
+ 	if (n < 0)
+ 		n = -n;
+ 	else
+ 		n = pg_mbstrlen_with_len(p, len) - n;
+ 	off = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text		   *str = PG_GETARG_TEXT_PP(0);
+ 	const char	   *p = VARDATA_ANY(str);
+ 	int				len = VARSIZE_ANY_EXHDR(str);
+ 	const char	   *endp = p + len;
+ 	text		   *result;
+ 	char		   *dst;
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	dst = (char*) VARDATA(result) + len;
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		/* multibyte version */
+ 		while (p < endp)
+ 		{
+ 			int		sz;
+ 
+ 			sz = pg_mblen(p);
+ 			dst -= sz;
+ 			memcpy(dst, p, sz);
+ 			p += sz;
+ 		}
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		while (p < endp)
+ 			*(--dst) = *p++;
+ 	}
+ 	
+ 	PG_RETURN_TEXT_P(result);
+ }
*** ./src/include/catalog/pg_proc.h.orig	2010-07-16 04:15:54.000000000 +0200
--- ./src/include/catalog/pg_proc.h	2010-07-24 08:35:37.009065744 +0200
***************
*** 2718,2723 ****
--- 2718,2735 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3094 ( concat			PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concat values to text");
+ DATA(insert OID = 3095 ( left			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("returns first n chars");
+ DATA(insert OID = 3096 ( right			PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("returns last n chars");
+ DATA(insert OID = 3097 ( reverse			PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("returns reversed string");
+ DATA(insert OID = 3098 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3099 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
*** ./src/include/utils/builtins.h.orig	2010-07-22 03:22:35.000000000 +0200
--- ./src/include/utils/builtins.h	2010-07-24 08:35:37.010064201 +0200
***************
*** 732,737 ****
--- 732,744 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
*** ./src/test/regress/expected/text.out.orig	2010-07-24 08:31:50.772205891 +0200
--- ./src/test/regress/expected/text.out	2010-07-24 09:14:05.000000000 +0200
***************
*** 51,53 ****
--- 51,126 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ select format('Hello % %', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+            format            
+ -----------------------------
+  users: 10, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ -- should to fail!
+ select format('Hello %');
+ ERROR:  too few parameters for format function
+ select format('Hello',10);
+ ERROR:  too many parameters for format function
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select i, left('ahoj', i) from generate_series(-5,5) t(i) order by i;
+  i  | left 
+ ----+------
+  -5 | 
+  -4 | 
+  -3 | a
+  -2 | ah
+  -1 | aho
+   0 | 
+   1 | a
+   2 | ah
+   3 | aho
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
+ select i, right('ahoj', i) from generate_series(-5,5) t(i) order by i;
+  i  | right 
+ ----+-------
+  -5 | 
+  -4 | 
+  -3 | j
+  -2 | oj
+  -1 | hoj
+   0 | 
+   1 | j
+   2 | oj
+   3 | hoj
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
*** ./src/test/regress/sql/text.sql.orig	2010-07-24 08:31:50.784065013 +0200
--- ./src/test/regress/sql/text.sql	2010-07-24 08:45:31.173064118 +0200
***************
*** 28,30 ****
--- 28,51 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ select format('Hello % %', 'World', 10);
+ select format('users: %, date: %', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ 
+ -- should to fail!
+ select format('Hello %');
+ select format('Hello',10);
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ 
+ select i, left('ahoj', i) from generate_series(-5,5) t(i) order by i;
+ select i, right('ahoj', i) from generate_series(-5,5) t(i) order by i;

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 70dab53..a25307f 100644
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 1251,1256 ****
--- 1251,1262 ----
      <primary>chr</primary>
     </indexterm>
     <indexterm>
+     <primary>concat</primary>
+    </indexterm>
+    <indexterm>
+     <primary>concat_ws</primary>
+    </indexterm>
+    <indexterm>
      <primary>convert</primary>
     </indexterm>
     <indexterm>
***************
*** 1266,1274 ****
--- 1272,1286 ----
      <primary>encode</primary>
     </indexterm>
     <indexterm>
+     <primary>format</primary>
+    </indexterm>
+    <indexterm>
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
+     <primary>left</primary>
+    </indexterm>
+    <indexterm>
      <primary>lpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1296,1301 ****
--- 1308,1319 ----
      <primary>replace</primary>
     </indexterm>
     <indexterm>
+     <primary>reverse</primary>
+    </indexterm>
+    <indexterm>
+     <primary>right</primary>
+    </indexterm>
+    <indexterm>
      <primary>rpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1376,1381 ****
--- 1394,1427 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>,
+          [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Concatenate all argument values. NULL arguments are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>concat_ws</function>(<parameter>sep</parameter> <type>text</type>,
+         <parameter>str</parameter> <type>"any"</type>,
+         [, <parameter>str</parameter> <type>"any"</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Concatenate all but first argument values. The first parameter is used
+         as a separator. NULL arguments are ignored.
+        </entry>
+        <entry><literal>concat_ws(',', 'abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde,2,22</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1454,1459 ****
--- 1500,1522 ----
        </row>       
  
        <row>
+        <entry>
+         <literal><function>format</function>(<parameter>formatstr</parameter> <type>text</type>
+         [, <parameter>value</parameter> <type>any</type> [...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Format argument values into a string like sprintf function in C library.
+         In addition to standard format characters, it supports <literal>%iq</>
+         (quoted identifier) and <literal>%lq</> (quoted literal).
+         Each format specifiler can also have length modifiler.
+         Write <literal>%%</> to emit a literal <literal>%</>.
+        </entry>
+        <entry><literal>format('%d %s xxx: %s', 10, 'foo', current_date)</literal></entry>
+        <entry><literal>10 foo xxx: 2010-03-05</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>initcap</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>text</type></entry>
         <entry>
***************
*** 1466,1471 ****
--- 1529,1548 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns first n chars of string. When n is negative, then returns chars from begin
+         to n char from right.
+        </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1680,1685 ****
--- 1757,1788 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type> )</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Returns last n chars of string. When n is negative, then returns chars from n char
+         to end of string
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index af28c15..c684053 100644
*** a/src/backend/utils/adt/varlena.c
--- b/src/backend/utils/adt/varlena.c
***************
*** 21,26 ****
--- 21,27 ----
  #include "libpq/md5.h"
  #include "libpq/pqformat.h"
  #include "miscadmin.h"
+ #include "parser/parse_coerce.h"
  #include "parser/scansup.h"
  #include "regex/regex.h"
  #include "utils/builtins.h"
*************** string_agg_finalfn(PG_FUNCTION_ARGS)
*** 3415,3417 ****
--- 3416,4155 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ static text *
+ concat_internal(const char *sepstr, int seplen, FunctionCallInfo fcinfo)
+ {
+ 	StringInfoData	str;
+ 	text		   *result;
+ 	int				i;
+ 
+ 	initStringInfo(&str);
+ 
+ 	for (i = (sepstr == NULL ? 0 : 1); i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid		valtype;
+ 			Datum	value;
+ 			Oid		typOutput;
+ 			bool	typIsVarlena;
+ 
+ 			if (i > 1)
+ 				appendBinaryStringInfo(&str, sepstr, seplen);
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
+ 			appendStringInfoString(&str,
+ 				OidOutputFunctionCall(typOutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	return result;
+ }
+ 
+ /*
+  * Concatenates arguments. NULL arguments are skipped.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	PG_RETURN_TEXT_P(concat_internal(NULL, 0, fcinfo));
+ }
+ 
+ /*
+  * Concatenates arguments. Each argument is separated with the first argument.
+  * NULL arguments are skipped.
+  */
+ Datum
+ text_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	text		   *sep;
+ 
+ 	/* return NULL when separator is NULL */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	sep = PG_GETARG_TEXT_PP(0);
+ 
+ 	PG_RETURN_TEXT_P(concat_internal(
+ 		VARDATA_ANY(sep), VARSIZE_ANY_EXHDR(sep), fcinfo));
+ }
+ 
+ /*
+  * Returns first n characters. When n is negative, returns chars without
+  * last |n| characters.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			rlen;
+ 
+ 	if (n < 0)
+ 		n = pg_mbstrlen_with_len(p, len) + n;
+ 	rlen = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+ }
+ 
+ /*
+  * Returns last n characters. When n is negative, returns string without
+  * first |n| characters.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			off;
+ 
+ 	if (n < 0)
+ 		n = -n;
+ 	else
+ 		n = pg_mbstrlen_with_len(p, len) - n;
+ 	off = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
+ }
+ 
+ /*
+  * Returns reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text		   *str = PG_GETARG_TEXT_PP(0);
+ 	const char	   *p = VARDATA_ANY(str);
+ 	int				len = VARSIZE_ANY_EXHDR(str);
+ 	const char	   *endp = p + len;
+ 	text		   *result;
+ 	char		   *dst;
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	dst = (char*) VARDATA(result) + len;
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		/* multibyte version */
+ 		while (p < endp)
+ 		{
+ 			int		sz;
+ 
+ 			sz = pg_mblen(p);
+ 			dst -= sz;
+ 			memcpy(dst, p, sz);
+ 			p += sz;
+ 		}
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		while (p < endp)
+ 			*(--dst) = *p++;
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ #define TXTFMT_ZERO				(1 << 0)
+ #define TXTFMT_SPACE			(1 << 1)
+ #define TXTFMT_PLUS				(1 << 2)
+ #define TXTFMT_MINUS			(1 << 3)
+ #define TXTFMT_STAR_WIDTH		(1 << 4)
+ #define TXTFMT_SHARP			(1 << 5)
+ #define TXTFMT_WIDTH			(1 << 6)
+ #define TXTFMT_PRECISION		(1 << 7)
+ #define TXTFMT_STAR_PRECISION	(1 << 8)
+ 
+ typedef struct FormatDesc
+ {
+ 	bits32		flags;
+ 	char		field_type;
+ 	char		quoting_type;
+ 	char		lenmod;
+ 	int32		width;
+ 	int32		precision;
+ } FormatDesc;
+ 
+ static Datum 
+ castValueTo(Datum value, Oid targetTypeId, Oid inputTypeId)
+ {
+ 	Oid					funcId;
+ 	CoercionPathType	pathtype;
+ 	FmgrInfo			finfo;
+ 	Datum				result;
+ 
+ 	if (inputTypeId != UNKNOWNOID)
+ 		pathtype = find_coercion_pathway(targetTypeId, inputTypeId, 
+ 									COERCION_EXPLICIT, 
+ 									&funcId);
+ 	else
+ 		pathtype = COERCION_PATH_COERCEVIAIO;
+ 	
+ 	switch (pathtype)
+ 	{
+ 		case COERCION_PATH_RELABELTYPE:
+ 			result = value;
+ 			break;
+ 		case COERCION_PATH_FUNC:
+ 			{
+ 				Assert(OidIsValid(funcId));
+ 				
+ 				fmgr_info(funcId, &finfo);
+ 				result = FunctionCall1(&finfo, value);
+ 			}
+ 			break;
+ 		
+ 		case COERCION_PATH_COERCEVIAIO:
+ 			{
+ 				Oid                     typOutput;
+ 				Oid			typinput;
+ 				bool            typIsVarlena;
+ 				Oid		typIOParam;
+ 				char 	*extval;
+ 		        
+ 				getTypeOutputInfo(inputTypeId, &typOutput, &typIsVarlena);
+ 				extval = OidOutputFunctionCall(typOutput, value);
+ 				
+ 				getTypeInputInfo(targetTypeId, &typinput, &typIOParam);
+ 				result = OidInputFunctionCall(typinput, extval, typIOParam, -1);
+ 			}
+ 			break;
+ 		
+ 		default:
+ 			elog(ERROR, "failed to find conversion function from %s to %s",
+ 					format_type_be(inputTypeId), format_type_be(targetTypeId));
+ 			/* be compiler quiet */
+ 			result = (Datum) 0;
+ 	}
+ 	
+ 	return result;
+ }
+ 
+ #define CHECK_PAD(symbol, pad_value) \
+ do { \
+ 	if (desc->flags & (pad_value)) \
+ 		ereport(ERROR, \
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE), \
+ 				 errmsg("invalid input for format function"), \
+ 				 errdetail("Format string is '%s'.", TextDatumGetCString(fmt)), \
+ 				 errhint("Symbol '%c' can be used only once.", (symbol)))); \
+ 	desc->flags |= (pad_value); \
+ } while(0);
+ 
+ /*
+  * parse and verify sprintf parameter
+  *
+  *	%[flags][width][.precision]specifier
+  */
+ static const char *
+ parsePlaceholder(const char *src,
+ 				 const char *end_ptr,
+ 				 FormatDesc *desc,
+ 				 text *fmt)
+ {
+ 	char		c;
+ 
+ 	desc->field_type = '\0';
+ 	desc->quoting_type = '\0';
+ 	desc->lenmod = '\0';
+ 	desc->flags = 0;
+ 	desc->width = 0;
+ 	desc->precision = 0;
+ 
+ 	while (src < end_ptr && desc->field_type == '\0')
+ 	{
+ 		c = *++src;
+ 		
+ 		/*
+ 		 * sprintf supports the most common formats that has a sense for high
+ 		 * level programming language with two additions - format tags "iq"
+ 		 * and "lq". These tags can be used in sense "identifier qouted"
+ 		 * and "literal quoted".
+ 		 */
+ 		if (c == 'i' || c == 'l')
+ 		{
+ 			/* look forward - can be a proprietary tag */
+ 			if (src < end_ptr && src[1] == 'q')
+ 			{
+ 				desc->field_type = *++src;
+ 				desc->quoting_type = c;
+ 
+ 				continue;
+ 			}
+ 		}
+ 
+ 		switch (c)
+ 		{
+ 			case '0':
+ 				CHECK_PAD('0', TXTFMT_ZERO);
+ 				break;
+ 			case ' ':
+ 				CHECK_PAD(' ', TXTFMT_SPACE);
+ 				break;
+ 			case '+':
+ 				CHECK_PAD('+', TXTFMT_PLUS);
+ 				break;
+ 			case '-':
+ 				CHECK_PAD('-', TXTFMT_MINUS);
+ 				break;
+ 			case '*':
+ 				CHECK_PAD('*', TXTFMT_STAR_WIDTH);
+ 				break;
+ 			case '#':
+ 				CHECK_PAD('#', TXTFMT_SHARP);
+ 				break;
+ 			case 'o': case 'i': case 'e': case 'E': case 'f': 
+ 			case 'g': case 'd': case 's': case 'x': case 'X': case 'q':
+ 				desc->field_type = *src;
+ 				break;
+ 			case '1': case '2': case '3': case '4':
+ 			case '5': case '6': case '7': case '8': case '9':
+ 				CHECK_PAD('9', TXTFMT_WIDTH);
+ 				desc->width = c - '0';
+ 				while (src < end_ptr && isdigit(src[1]))
+ 					desc->width = desc->width * 10 + *++src - '0';
+ 				break;
+ 			case '.':
+ 				if (src < end_ptr)
+ 				{
+ 					if (src[1] == '*')
+ 					{
+ 						CHECK_PAD('.', TXTFMT_STAR_PRECISION);
+ 						src++;
+ 					}
+ 					else
+ 					{
+ 						/*
+ 						 * when no one digit is entered, then precision
+ 						 * is zero - digits are optional.
+ 						 */
+ 						CHECK_PAD('.', TXTFMT_PRECISION);
+ 						while (src < end_ptr && isdigit(src[1]))
+ 							desc->precision = desc->precision * 10 +
+ 											  *++src - '0';
+ 					}
+ 				}
+ 				else 
+ 					ereport(ERROR,
+ 							(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 							 errmsg("invalid input for format function"),
+ 							 errdetail("missing precision value")));
+ 				break;
+ 
+ 			default:
+ 				ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("unsupported format tag '%c'", c)));
+ 		}
+ 	}
+ 
+ 	if (desc->field_type == '\0')
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("invalid input for format function")));
+ 
+ 	return src;
+ }
+ 
+ #define MAX_FORMAT_SIZE		32
+ 
+ static void
+ currentFormat(char str[], const FormatDesc *desc)
+ {
+ 	size_t		len = 0;
+ 
+ 	str[len++] = '%';
+ 	
+ 	if (desc->flags & TXTFMT_ZERO)
+ 		str[len++] = '0';
+ 
+ 	if (desc->flags & TXTFMT_MINUS)
+ 		str[len++] = '-';
+ 
+ 	if (desc->flags & TXTFMT_PLUS)
+ 		str[len++] = '+';
+ 		
+ 	if (desc->flags & TXTFMT_SPACE)
+ 		str[len++] = ' ';
+ 		
+ 	if (desc->flags & TXTFMT_SHARP)
+ 		str[len++] = '#';
+ 
+ 	if ((desc->flags & TXTFMT_WIDTH) ||
+ 		(desc->flags & TXTFMT_STAR_WIDTH))
+ 		str[len++] = '*';
+ 		
+ 	if ((desc->flags & TXTFMT_PRECISION) ||
+ 		(desc->flags & TXTFMT_STAR_PRECISION))
+ 	{
+ 		memcpy(str + len, ".*", 2);
+ 		len += 2;
+ 	}
+ 
+ 	if (desc->lenmod == 'l')
+ 	{
+ 		size_t	sz = strlen(INT64_FORMAT) - 2;
+ 		memcpy(str + len, INT64_FORMAT + 1, sz);
+ 		len += sz;
+ 	}
+ 	else if (desc->lenmod != '\0')
+ 		str[len++] = desc->lenmod;
+ 
+ 	str[len++] = desc->field_type;
+ 	str[len] = '\0';
+ }
+ 
+ /*
+  * simulate %+width.precion%s format of sformat function 
+  */
+ static void 
+ append_string(StringInfo str, FormatDesc *desc, const char *string)
+ {
+ 	int	nchars = 0;				/* length of substring in chars */
+ 	int	binlen = 0;				/* length of substring in bytes */
+ 
+ 	/*
+ 	 * apply precision - it means "show only first n chars", for strings - this flag is 
+ 	 * ignored for proprietary tags %lq and iq, because we can't to show a first n chars 
+ 	 * from possible quoted value. 
+ 	 */
+ 	if (desc->flags & TXTFMT_PRECISION && desc->field_type != 'q')
+ 	{
+ 		const char *ptr = string;
+ 		int	  len = desc->precision;
+ 		
+ 		if (pg_database_encoding_max_length() > 1)
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr += pg_mblen(ptr);
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		else
+ 		{
+ 			while (*ptr && len > 0)
+ 			{
+ 				ptr++;
+ 				len--;
+ 				nchars++;
+ 			}
+ 		}
+ 		
+ 		binlen = ptr - string;
+ 	}
+ 	else
+ 	{
+ 		/* there isn't precion specified, show complete string */
+ 		nchars = pg_mbstrlen(string);
+ 		binlen = strlen(string);
+ 	}
+ 	
+ 	/* when width is specified, then we have to solve left or right align */
+ 	if (desc->flags & TXTFMT_WIDTH)
+ 	{
+ 		if (desc->width > nchars)
+ 		{
+ 			/* add neccessary spaces to begin or end */
+ 			if (desc->flags & TXTFMT_MINUS)
+ 			{
+ 				/* allign to left */
+ 				appendBinaryStringInfo(str, string, binlen);
+ 				appendStringInfoSpaces(str, desc->width - nchars);
+ 			}
+ 			else
+ 			{
+ 				/* allign to right */
+ 				appendStringInfoSpaces(str, desc->width - nchars);
+ 				appendBinaryStringInfo(str, string, binlen);
+ 			}
+ 
+ 		}
+ 		else
+ 			/* just copy result to output */
+ 			appendBinaryStringInfo(str, string, binlen);
+ 	}
+ 	else
+ 		/* just copy result to output */
+ 		appendBinaryStringInfo(str, string, binlen);
+ }
+ 
+ /*
+  * Set width and precision when they are defined dynamicaly
+  */
+ static int
+ setWidthAndPrecision(FormatDesc *desc,
+ 					 FunctionCallInfoData *fcinfo,
+ 					 int current)
+ {
+ 
+ 	/* 
+ 	 * don't allow ambiguous definition
+ 	 */
+ 	if ((desc->flags & TXTFMT_WIDTH) && (desc->flags & TXTFMT_STAR_WIDTH))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("invalid input for format function"),
+ 				 errdetail("ambiguous width definition")));
+ 
+ 	if ((desc->flags & TXTFMT_PRECISION) && (desc->flags & TXTFMT_STAR_PRECISION))
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("invalid input for format function"),
+ 				 errdetail("ambiguous precision definition")));
+ 	if (desc->flags & TXTFMT_STAR_WIDTH)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters for format function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		desc->width = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flag */
+ 		desc->flags ^= TXTFMT_STAR_WIDTH;
+ 		desc->flags |= TXTFMT_WIDTH;
+ 		current += 1;
+ 	}
+ 	
+ 	if (desc->flags & TXTFMT_STAR_PRECISION)
+ 	{
+ 		if (current >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters for format function")));
+ 		
+ 		if (PG_ARGISNULL(current))
+ 			ereport(ERROR,
+ 				(errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 				 errmsg("null value not allowed"),
+ 				 errhint("width (%dth) arguments is NULL", current)));
+ 		
+ 		desc->precision = DatumGetInt32(castValueTo(PG_GETARG_DATUM(current), INT4OID, 
+ 									get_fn_expr_argtype(fcinfo->flinfo, current)));
+ 		/* reset flags */
+ 		desc->flags ^= TXTFMT_STAR_PRECISION;
+ 		desc->flags |= TXTFMT_PRECISION;
+ 		current += 1;
+ 	}
+ 	
+ 	return current;
+ }
+ 
+ /*
+  * Replaces % symbols with the external representation of the arguments.
+  *
+  * Syntax: text_format(format text [, arg "any"] ...) RETURNS text
+  */
+ Datum
+ text_format(PG_FUNCTION_ARGS)
+ {
+ 	text		   *fmt;
+ 	StringInfoData	str;
+ 	int				arg;
+ 	const char	   *start_ptr,
+ 				   *end_ptr,
+ 				   *cp;
+ 	text		   *result;
+ 
+ 	/* returns null when format string is null */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	fmt = PG_GETARG_TEXT_PP(0);
+ 	start_ptr = VARDATA_ANY(fmt);
+ 	end_ptr = start_ptr + VARSIZE_ANY_EXHDR(fmt) - 1;
+ 
+ 	initStringInfo(&str);
+ 
+ 	arg = 1;
+ 	for (cp = start_ptr; cp <= end_ptr; cp++)
+ 	{
+ 		Oid			typOutput;
+ 		bool		typIsVarlena;
+ 		Datum		value;
+ 		Oid			valtype;
+ 		FormatDesc	desc;
+ 
+ 		if (cp[0] != '%')
+ 		{
+ 			appendStringInfoChar(&str, cp[0]);
+ 			continue;
+ 		}
+ 
+ 		if (cp < end_ptr && cp[1] == '%')
+ 		{
+ 			/* when cp is not pointer on last char, check %% */
+ 			appendStringInfoChar(&str, cp[1]);
+ 			cp++;
+ 			continue;
+ 		}
+ 
+ 		cp = parsePlaceholder(cp, end_ptr, &desc, fmt);
+ 		arg = setWidthAndPrecision(&desc, fcinfo, arg);
+ 
+ 		if (arg >= PG_NARGS())
+ 			ereport(ERROR,
+ 					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 					 errmsg("too few parameters for format function")));
+ 
+ 		/*
+ 		 * NULL value is printed as <NULL> in normal cases, but NULL for tag
+ 		 * %lq case - similar to quote_nullable. NULL cannot be used as
+ 		 * identifier - so exception is raised when tag is %iq.
+ 		 */
+ 		if (PG_ARGISNULL(arg))
+ 		{
+ 			if (desc.field_type != 'q')
+ 				append_string(&str, &desc, "<NULL>");
+ 			else if (desc.quoting_type == 'i')
+ 				ereport(ERROR,
+ 					    (errcode(ERRCODE_NULL_VALUE_NOT_ALLOWED),
+ 					     errmsg("null value not allowed"),
+ 					     errhint("cannot to use NULL as identifier")));
+ 			else						
+ 				append_string(&str, &desc, "NULL");
+ 			arg++;
+ 			continue;
+ 		}
+ 
+ 		/* append n-th value */
+ 		value = PG_GETARG_DATUM(arg);
+ 		valtype = get_fn_expr_argtype(fcinfo->flinfo, arg);
+ 
+ 		/* convert value to target type */
+ 		switch (desc.field_type)
+ 		{
+ 			case 'o': case 'd': case 'i': case 'x': case 'X':
+ 				{
+ 					int64	target_value;
+ 					char	format[MAX_FORMAT_SIZE];
+ 
+ 					desc.lenmod = 'l';
+ 					target_value = DatumGetInt64(castValueTo(value,
+ 													INT8OID, valtype));
+ 					currentFormat(format, &desc);
+ 
+ 					if ((desc.flags & TXTFMT_WIDTH) &&
+ 						(desc.flags & TXTFMT_PRECISION))
+ 						appendStringInfo(&str, format, desc.width,
+ 										 desc.precision, target_value);
+ 					else if (desc.flags & TXTFMT_WIDTH)
+ 						appendStringInfo(&str, format, desc.width,
+ 										 target_value);
+ 					else if (desc.flags & TXTFMT_PRECISION)
+ 						appendStringInfo(&str, format, desc.precision,
+ 										 target_value);
+ 					else
+ 						appendStringInfo(&str, format, target_value);
+ 				}
+ 				break;
+ 			case 'e': case 'f': case 'g': case 'G': case 'E':
+ 				{
+ 					float8	target_value;
+ 					char	format[MAX_FORMAT_SIZE];
+ 					
+ 					target_value = DatumGetFloat8(castValueTo(value,
+ 														FLOAT8OID, valtype));
+ 					currentFormat(format, &desc);
+ 					
+ 					if ((desc.flags & TXTFMT_WIDTH) &&
+ 						(desc.flags & TXTFMT_PRECISION))
+ 						appendStringInfo(&str, format, desc.width,
+ 										 desc.precision, target_value);
+ 					else if (desc.flags & TXTFMT_WIDTH)
+ 						appendStringInfo(&str, format, desc.width,
+ 										 target_value);
+ 					else if (desc.flags & TXTFMT_PRECISION)
+ 						appendStringInfo(&str, format, desc.precision,
+ 										 target_value);
+ 					else
+ 						appendStringInfo(&str, format, target_value);
+ 				}
+ 				break;
+ 			case 's':
+ 				{
+ 					char		*target_value;
+ 
+ 					getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
+ 					target_value = OidOutputFunctionCall(typOutput, value);
+ 					append_string(&str, &desc, target_value);
+ 					pfree(target_value);
+ 				}
+ 				break;
+ 			case 'q':
+ 				{
+ 					char		*target_value;
+ 
+ 					getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
+ 					target_value = OidOutputFunctionCall(typOutput, value);
+ 			
+ 					if (desc.quoting_type == 'i')
+ 					{
+ 						const char *quoted_str;
+ 						
+ 						quoted_str = quote_identifier(target_value);
+ 						append_string(&str, &desc, quoted_str);
+ 					}
+ 					else
+ 					{
+ 						text	*txt;
+ 						text	*quoted_txt;
+ 						char	*quoted_str;
+ 
+ 						txt = cstring_to_text(target_value);
+ 						quoted_txt = DatumGetTextP(DirectFunctionCall1(quote_literal, PointerGetDatum(txt)));
+ 						quoted_str = text_to_cstring(quoted_txt);
+ 						append_string(&str, &desc, quoted_str);
+ 
+ 						pfree(quoted_str);
+ 					}
+ 					pfree(target_value);
+ 				}
+ 				break;
+ 			default:
+ 				elog(ERROR, "unknown format: %c", desc.field_type);
+ 		}
+ 		arg++;
+ 	}
+ 
+ 	/* check if all arguments are used */
+ 	if (arg != PG_NARGS())
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ 				 errmsg("too many parameters for format function")));
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 
+ 	pfree(str.data);
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
+ 
+ /*
+  * Non-variadic version of text_format only to validate format string.
+  */
+ Datum
+ text_format_nv(PG_FUNCTION_ARGS)
+ {
+ 	return text_format(fcinfo);
+ }
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 6036493..3547cee 100644
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
*************** DESCR("I/O");
*** 2718,2723 ****
--- 2718,2737 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3037 ( concat		PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concatenate values to text");
+ DATA(insert OID = 3038 ( concat_ws	PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_concat_ws _null_ _null_ _null_ ));
+ DESCR("concatenate values to text with separators");
+ DATA(insert OID = 3039 ( left		PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("return the first n characters");
+ DATA(insert OID = 3040 ( right		PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("return the last n characters");
+ DATA(insert OID = 3041 ( reverse	PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("reverse text");
+ DATA(insert OID = 3042 ( format		PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_format _null_ _null_ _null_ ));
+ DESCR("format text message");
+ DATA(insert OID = 3043 ( format		PGNSP PGUID 12 1 0 0 f f f f f s 1 0 25 "25" _null_ _null_ _null_ _null_  text_format_nv _null_ _null_ _null_ ));
+ DESCR("format text message");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index 0c92334..c45faf1 100644
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
*************** extern Datum string_agg_transfn(PG_FUNCT
*** 732,737 ****
--- 732,745 ----
  extern Datum string_agg_delim_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_concat_ws(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ extern Datum text_format(PG_FUNCTION_ARGS);
+ extern Datum text_format_nv(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
diff --git a/src/test/regress/expected/text.out b/src/test/regress/expected/text.out
index 08d002f..faf9f91 100644
*** a/src/test/regress/expected/text.out
--- b/src/test/regress/expected/text.out
*************** ERROR:  operator does not exist: integer
*** 51,53 ****
--- 51,255 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ -- format
+ select format('Hello %s %s', 'World', 10);
+      format     
+ ----------------
+  Hello World 10
+ (1 row)
+ 
+ select format('%%%s%%, date: %s', 10, to_date('20080809','YYYYMMDD'));
+          format         
+ ------------------------
+  %10%, date: 08-09-2008
+ (1 row)
+ 
+ select format('Hello');
+  format 
+ --------
+  Hello
+ (1 row)
+ 
+ select format('Hello %s'); -- error
+ ERROR:  too few parameters for format function
+ select format('Hello',10); -- error
+ ERROR:  too many parameters for format function
+ select format('>>>%10s %10d<<<', 'hello', 10);
+            format            
+ -----------------------------
+  >>>     hello         10<<<
+ (1 row)
+ 
+ select format('>>>%-10s<<<', 'hello');
+       format      
+ ------------------
+  >>>hello     <<<
+ (1 row)
+ 
+ select format('>>>%5.2<<<', 'abcde'); -- error
+ ERROR:  unsupported format tag '<'
+ select format('>>>%*s<<<', 10, 'abcdef');
+       format      
+ ------------------
+  >>>    abcdef<<<
+ (1 row)
+ 
+ select format('>>>%*s<<<', 10); -- error
+ ERROR:  too few parameters for format function
+ select format('%010d', 10);
+    format   
+ ------------
+  0000000010
+ (1 row)
+ 
+ select format('%.6d', 10);
+  format 
+ --------
+  000010
+ (1 row)
+ 
+ select format('%'); -- error
+ ERROR:  invalid input for format function
+ select format('%d', 100.0/3.0);
+  format 
+ --------
+  33
+ (1 row)
+ 
+ select format('%e', 100.0/3.0);
+     format    
+ --------------
+  3.333333e+01
+ (1 row)
+ 
+ select format('%f', 100.0/3.0);
+   format   
+ -----------
+  33.333333
+ (1 row)
+ 
+ select format('%g', 100.0/3.0);
+  format  
+ ---------
+  33.3333
+ (1 row)
+ 
+ select format('%7.4e', 100.0/3.0);
+    format   
+ ------------
+  3.3333e+01
+ (1 row)
+ 
+ select format('%7.4f', 100.0/3.0);
+  format  
+ ---------
+  33.3333
+ (1 row)
+ 
+ select format('%7.4g', 100.0/3.0);
+  format  
+ ---------
+    33.33
+ (1 row)
+ 
+ select format('%d', NULL);
+  format 
+ --------
+  <NULL>
+ (1 row)
+ 
+ select format('some quotes: %q %lq %iq', 'tab', 'tab', 'tab');
+             format            
+ ------------------------------
+  some quotes: 'tab' 'tab' tab
+ (1 row)
+ 
+ select format('some quotes: %q %lq %iq', 'a''"b', 'a''"b', 'a''"b');
+                 format                
+ --------------------------------------
+  some quotes: 'a''"b' 'a''"b' "a'""b"
+ (1 row)
+ 
+ select format('null literal: %lq', NULL);
+        format       
+ --------------------
+  null literal: NULL
+ (1 row)
+ 
+ select format('null identifier: %iq', NULL); -- error
+ ERROR:  null value not allowed
+ HINT:  cannot to use NULL as identifier
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_ws(',',10,20,null,30);
+  concat_ws 
+ -----------
+  10,20,30
+ (1 row)
+ 
+ select concat_ws('',10,20,null,30);
+  concat_ws 
+ -----------
+  102030
+ (1 row)
+ 
+ select concat_ws(NULL,10,20,null,30) is null; -- yes, have to be true
+  ?column? 
+ ----------
+  t
+ (1 row)
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select i, left('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+  i  | left 
+ ----+------
+  -5 | 
+  -4 | 
+  -3 | a
+  -2 | ah
+  -1 | aho
+   0 | 
+   1 | a
+   2 | ah
+   3 | aho
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
+ select i, right('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+  i  | right 
+ ----+-------
+  -5 | 
+  -4 | 
+  -3 | j
+  -2 | oj
+  -1 | hoj
+   0 | 
+   1 | j
+   2 | oj
+   3 | hoj
+   4 | ahoj
+   5 | ahoj
+ (11 rows)
+ 
diff --git a/src/test/regress/sql/text.sql b/src/test/regress/sql/text.sql
index b739e56..90d4e67 100644
*** a/src/test/regress/sql/text.sql
--- b/src/test/regress/sql/text.sql
*************** select 'four: ' || 2+2;
*** 28,30 ****
--- 28,75 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ -- format
+ select format('Hello %s %s', 'World', 10);
+ select format('%%%s%%, date: %s', 10, to_date('20080809','YYYYMMDD'));
+ select format('Hello');
+ select format('Hello %s'); -- error
+ select format('Hello',10); -- error
+ select format('>>>%10s %10d<<<', 'hello', 10);
+ select format('>>>%-10s<<<', 'hello');
+ select format('>>>%5.2<<<', 'abcde'); -- error
+ select format('>>>%*s<<<', 10, 'abcdef');
+ select format('>>>%*s<<<', 10); -- error
+ select format('%010d', 10);
+ select format('%.6d', 10);
+ select format('%'); -- error
+ 
+ select format('%d', 100.0/3.0);
+ select format('%e', 100.0/3.0);
+ select format('%f', 100.0/3.0);
+ select format('%g', 100.0/3.0);
+ select format('%7.4e', 100.0/3.0);
+ select format('%7.4f', 100.0/3.0);
+ select format('%7.4g', 100.0/3.0);
+ select format('%d', NULL);
+ 
+ select format('some quotes: %q %lq %iq', 'tab', 'tab', 'tab');
+ select format('some quotes: %q %lq %iq', 'a''"b', 'a''"b', 'a''"b');
+ select format('null literal: %lq', NULL);
+ select format('null identifier: %iq', NULL); -- error
+ 
+ /*
+  * concat tests
+  */
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws(',',10,20,null,30);
+ select concat_ws('',10,20,null,30);
+ select concat_ws(NULL,10,20,null,30) is null; -- yes, have to be true
+ 
+ /*
+  * others tests
+  */
+ select reverse('abcde');
+ select i, left('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+ select i, right('ahoj', i) from generate_series(-5, 5) t(i) order by i;

--- doc/src/sgml/xfunc.sgml.orig	2010-05-14 23:00:23.000000000 +0200
+++ doc/src/sgml/xfunc.sgml	2010-05-15 01:52:52.000000000 +0200
@@ -859,7 +859,8 @@
      output parameters, like this:
 
 <programlisting>
-CREATE FUNCTION sum_n_product_with_tab (x int, OUT sum int, OUT product int) RETURNS SETOF record AS $$
+CREATE FUNCTION sum_n_product_with_tab (x int, OUT sum int, OUT product int)
+RETURNS SETOF record AS $$
     SELECT $1 + tab.y, $1 * tab.y FROM tab;
 $$ LANGUAGE SQL;
 </programlisting>
@@ -957,7 +958,8 @@
      done this way:
 
 <programlisting>
-CREATE FUNCTION sum_n_product_with_tab (x int) RETURNS TABLE(sum int, product int) AS $$
+CREATE FUNCTION sum_n_product_with_tab (x int)
+RETURNS TABLE(sum int, product int) AS $$
     SELECT $1 + tab.y, $1 * tab.y FROM tab;
 $$ LANGUAGE SQL;
 </programlisting>
@@ -1026,7 +1028,8 @@
     SELECT 1;
 $$ LANGUAGE SQL;
 ERROR:  cannot determine result data type
-DETAIL:  A function returning a polymorphic type must have at least one polymorphic argument.
+DETAIL:  A function returning a polymorphic type must have 
+                                         at least one polymorphic argument.
 </screen>
     </para>
 
@@ -2075,7 +2078,7 @@
 <programlisting>
 PG_FUNCTION_INFO_V1(funcname);
 </programlisting>
-     must appear in the same source file.  (Conventionally. it's
+     must appear in the same source file.  (Conventionally, it's
      written just before the function itself.)  This macro call is not
      needed for <literal>internal</>-language functions, since
      <productname>PostgreSQL</> assumes that all internal functions

--- xfunc.sgml.orig	2010-07-29 22:18:27.000000000 +0200
+++ xfunc.sgml	2010-07-29 22:32:53.000000000 +0200
@@ -1067,13 +1067,13 @@
  abc
 (1 row)
 
-CREATE FUNCTION concat(text, VARIADIC anyarray) RETURNS text AS $$
+CREATE FUNCTION concat_values(text, VARIADIC anyarray) RETURNS text AS $$
     SELECT array_to_string($2, $1);
 $$ LANGUAGE SQL;
 
-SELECT concat('|', 1, 4, 2);
- concat 
---------
+SELECT concat_values('|', 1, 4, 2);
+ concat_values 
+---------------
  1|4|2
 (1 row)
 </screen>

diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dda561f..e6923c3 100644
*** a/doc/src/sgml/func.sgml
--- b/doc/src/sgml/func.sgml
***************
*** 1251,1256 ****
--- 1251,1262 ----
      <primary>chr</primary>
     </indexterm>
     <indexterm>
+     <primary>concat</primary>
+    </indexterm>
+    <indexterm>
+     <primary>concat_ws</primary>
+    </indexterm>
+    <indexterm>
      <primary>convert</primary>
     </indexterm>
     <indexterm>
***************
*** 1269,1274 ****
--- 1275,1283 ----
      <primary>initcap</primary>
     </indexterm>
     <indexterm>
+     <primary>left</primary>
+    </indexterm>
+    <indexterm>
      <primary>lpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1296,1301 ****
--- 1305,1316 ----
      <primary>replace</primary>
     </indexterm>
     <indexterm>
+     <primary>reverse</primary>
+    </indexterm>
+    <indexterm>
+     <primary>right</primary>
+    </indexterm>
+    <indexterm>
      <primary>rpad</primary>
     </indexterm>
     <indexterm>
***************
*** 1376,1381 ****
--- 1391,1424 ----
  
        <row>
         <entry>
+         <literal><function>concat</function>(<parameter>str</parameter> <type>"any"</type>
+          [, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Concatenate all arguments. NULL arguments are ignored.
+        </entry>
+        <entry><literal>concat('abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde222</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>concat_ws</function>(<parameter>sep</parameter> <type>text</type>,
+         <parameter>str</parameter> <type>"any"</type>
+         [, <parameter>str</parameter> <type>"any"</type> [, ...] ])</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Concatenate all but first arguments with separators. The first
+         parameter is used as a separator. NULL arguments are ignored.
+        </entry>
+        <entry><literal>concat_ws(',', 'abcde', 2, NULL, 22)</literal></entry>
+        <entry><literal>abcde,2,22</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>convert</function>(<parameter>string</parameter> <type>bytea</type>,
          <parameter>src_encoding</parameter> <type>name</type>,
          <parameter>dest_encoding</parameter> <type>name</type>)</literal>
***************
*** 1466,1471 ****
--- 1509,1528 ----
        </row>
  
        <row>
+        <entry>
+         <literal><function>left</function>(<parameter>str</parameter> <type>text</type>,
+         <parameter>n</parameter> <type>int</type>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Return first <replaceable>n</> characters in the string. When <replaceable>n</>
+         is negative, return all but last |<replaceable>n</>| characters.
+         </entry>
+        <entry><literal>left('abcde', 2)</literal></entry>
+        <entry><literal>ab</literal></entry>
+       </row>
+ 
+       <row>
         <entry><literal><function>length</function>(<parameter>string</parameter>)</literal></entry>
         <entry><type>int</type></entry>
         <entry>
***************
*** 1680,1685 ****
--- 1737,1768 ----
  
        <row>
         <entry>
+         <literal><function>reverse</function>(<parameter>str</parameter>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Return reversed string.
+        </entry>
+        <entry><literal>reverse('abcde')</literal></entry>
+        <entry><literal>edcba</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
+         <literal><function>right</function>(<parameter>str</parameter> <type>text</type>,
+          <parameter>n</parameter> <type>int</type>)</literal>
+        </entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Return last <replaceable>n</> characters in the string. When <replaceable>n</>
+         is negative, return all but first |<replaceable>n</>| characters.
+        </entry>
+        <entry><literal>right('abcde', 2)</literal></entry>
+        <entry><literal>de</literal></entry>
+       </row>
+ 
+       <row>
+        <entry>
          <literal><function>rpad</function>(<parameter>string</parameter> <type>text</type>,
          <parameter>length</parameter> <type>int</type>
          <optional>, <parameter>fill</parameter> <type>text</type></optional>)</literal>
diff --git a/src/backend/utils/adt/varlena.c b/src/backend/utils/adt/varlena.c
index 94766cd..0dd4bc1 100644
*** a/src/backend/utils/adt/varlena.c
--- b/src/backend/utils/adt/varlena.c
*************** string_agg_finalfn(PG_FUNCTION_ARGS)
*** 3556,3558 ****
--- 3556,3704 ----
  	else
  		PG_RETURN_NULL();
  }
+ 
+ static text *
+ concat_internal(const char *sepstr, int seplen, int argidx, FunctionCallInfo fcinfo)
+ {
+ 	StringInfoData	str;
+ 	text		   *result;
+ 	int				i;
+ 
+ 	initStringInfo(&str);
+ 
+ 	for (i = argidx; i < PG_NARGS(); i++)
+ 	{
+ 		if (!PG_ARGISNULL(i))
+ 		{
+ 			Oid		valtype;
+ 			Datum	value;
+ 			Oid		typOutput;
+ 			bool	typIsVarlena;
+ 
+ 			if (i > argidx)
+ 				appendBinaryStringInfo(&str, sepstr, seplen);
+ 
+ 			/* append n-th value */
+ 			value = PG_GETARG_DATUM(i);
+ 			valtype = get_fn_expr_argtype(fcinfo->flinfo, i);
+ 			getTypeOutputInfo(valtype, &typOutput, &typIsVarlena);
+ 			appendStringInfoString(&str,
+ 				OidOutputFunctionCall(typOutput, value));
+ 		}
+ 	}
+ 
+ 	result = cstring_to_text_with_len(str.data, str.len);
+ 	pfree(str.data);
+ 
+ 	return result;
+ }
+ 
+ /*
+  * Concatenate all arguments. NULL arguments are ignored.
+  */
+ Datum
+ text_concat(PG_FUNCTION_ARGS)
+ {
+ 	PG_RETURN_TEXT_P(concat_internal(NULL, 0, 0, fcinfo));
+ }
+ 
+ /*
+  * Concatenate all but first argument values with separators. The first
+  * parameter is used as a separator. NULL arguments are ignored.
+  */
+ Datum
+ text_concat_ws(PG_FUNCTION_ARGS)
+ {
+ 	text		   *sep;
+ 
+ 	/* return NULL when separator is NULL */
+ 	if (PG_ARGISNULL(0))
+ 		PG_RETURN_NULL();
+ 
+ 	sep = PG_GETARG_TEXT_PP(0);
+ 
+ 	PG_RETURN_TEXT_P(concat_internal(
+ 		VARDATA_ANY(sep), VARSIZE_ANY_EXHDR(sep), 1, fcinfo));
+ }
+ 
+ /*
+  * Return first n characters in the string. When n is negative,
+  * return all but last |n| characters.
+  */
+ Datum
+ text_left(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			rlen;
+ 
+ 	if (n < 0)
+ 		n = pg_mbstrlen_with_len(p, len) + n;
+ 	rlen = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p, rlen));
+ }
+ 
+ /*
+  * Return last n characters in the string. When n is negative,
+  * return all but first |n| characters.
+  */
+ Datum
+ text_right(PG_FUNCTION_ARGS)
+ {
+ 	text	   *str = PG_GETARG_TEXT_PP(0);
+ 	const char *p = VARDATA_ANY(str);
+ 	int			len = VARSIZE_ANY_EXHDR(str);
+ 	int			n = PG_GETARG_INT32(1);
+ 	int			off;
+ 
+ 	if (n < 0)
+ 		n = -n;
+ 	else
+ 		n = pg_mbstrlen_with_len(p, len) - n;
+ 	off = pg_mbcharcliplen(p, len, n);
+ 
+ 	PG_RETURN_TEXT_P(cstring_to_text_with_len(p + off, len - off));
+ }
+ 
+ /*
+  * Return reversed string
+  */
+ Datum
+ text_reverse(PG_FUNCTION_ARGS)
+ {
+ 	text		   *str = PG_GETARG_TEXT_PP(0);
+ 	const char	   *p = VARDATA_ANY(str);
+ 	int				len = VARSIZE_ANY_EXHDR(str);
+ 	const char	   *endp = p + len;
+ 	text		   *result;
+ 	char		   *dst;
+ 
+ 	result = palloc(len + VARHDRSZ);
+ 	dst = (char*) VARDATA(result) + len;
+ 	SET_VARSIZE(result, len + VARHDRSZ);
+ 
+ 	if (pg_database_encoding_max_length() > 1)
+ 	{
+ 		/* multibyte version */
+ 		while (p < endp)
+ 		{
+ 			int		sz;
+ 
+ 			sz = pg_mblen(p);
+ 			dst -= sz;
+ 			memcpy(dst, p, sz);
+ 			p += sz;
+ 		}
+ 	}
+ 	else
+ 	{
+ 		/* single byte version */
+ 		while (p < endp)
+ 			*(--dst) = *p++;
+ 	}
+ 
+ 	PG_RETURN_TEXT_P(result);
+ }
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index 1c53418..f6364cd 100644
*** a/src/include/catalog/pg_proc.h
--- b/src/include/catalog/pg_proc.h
*************** DESCR("I/O");
*** 2722,2727 ****
--- 2722,2737 ----
  DATA(insert OID = 1799 (  oidout		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2275 "26" _null_ _null_ _null_ _null_ oidout _null_ _null_ _null_ ));
  DESCR("I/O");
  
+ DATA(insert OID = 3058 ( concat		PGNSP PGUID 12 1 0 2276 f f f f f s 1 0 25 "2276" "{2276}" "{v}" _null_ _null_  text_concat _null_ _null_ _null_ ));
+ DESCR("concatenate values");
+ DATA(insert OID = 3059 ( concat_ws	PGNSP PGUID 12 1 0 2276 f f f f f s 2 0 25 "25 2276" "{25,2276}" "{i,v}" _null_ _null_  text_concat_ws _null_ _null_ _null_ ));
+ DESCR("concatenate values with separators");
+ DATA(insert OID = 3060 ( left		PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_left _null_ _null_ _null_ ));
+ DESCR("return the first n characters");
+ DATA(insert OID = 3061 ( right		PGNSP PGUID 12 1 0 0 f f f t f i 2 0 25 "25 23" _null_ _null_ _null_ _null_  text_right _null_ _null_ _null_ ));
+ DESCR("return the last n characters");
+ DATA(insert OID = 3062 ( reverse	PGNSP PGUID 12 1 0 0 f f f t f i 1 0 25 "25" _null_ _null_ _null_ _null_  text_reverse  _null_ _null_ _null_ ));
+ DESCR("reverse text");
  
  DATA(insert OID = 1810 (  bit_length	   PGNSP PGUID 14 1 0 0 f f f t f i 1 0 23 "17" _null_ _null_ _null_ _null_ "select pg_catalog.octet_length($1) * 8" _null_ _null_ _null_ ));
  DESCR("length in bits");
diff --git a/src/include/utils/builtins.h b/src/include/utils/builtins.h
index a4c6180..f064a89 100644
*** a/src/include/utils/builtins.h
--- b/src/include/utils/builtins.h
*************** extern Datum pg_column_size(PG_FUNCTION_
*** 733,738 ****
--- 733,744 ----
  extern Datum string_agg_transfn(PG_FUNCTION_ARGS);
  extern Datum string_agg_finalfn(PG_FUNCTION_ARGS);
  
+ extern Datum text_concat(PG_FUNCTION_ARGS);
+ extern Datum text_concat_ws(PG_FUNCTION_ARGS);
+ extern Datum text_left(PG_FUNCTION_ARGS);
+ extern Datum text_right(PG_FUNCTION_ARGS);
+ extern Datum text_reverse(PG_FUNCTION_ARGS);
+ 
  /* version.c */
  extern Datum pgsql_version(PG_FUNCTION_ARGS);
  
diff --git a/src/test/regress/expected/text.out b/src/test/regress/expected/text.out
index 08d002f..84f4a5c 100644
*** a/src/test/regress/expected/text.out
--- b/src/test/regress/expected/text.out
*************** ERROR:  operator does not exist: integer
*** 51,53 ****
--- 51,120 ----
  LINE 1: select 3 || 4.0;
                   ^
  HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
+ /*
+  * string functions
+  */
+ select concat('one');
+  concat 
+ --------
+  one
+ (1 row)
+ 
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+         concat        
+ ----------------------
+  123hellotf03-09-2010
+ (1 row)
+ 
+ select concat_ws('#','one');
+  concat_ws 
+ -----------
+  one
+ (1 row)
+ 
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+          concat_ws          
+ ----------------------------
+  1#2#3#hello#t#f#03-09-2010
+ (1 row)
+ 
+ select concat_ws(',',10,20,null,30);
+  concat_ws 
+ -----------
+  10,20,30
+ (1 row)
+ 
+ select concat_ws('',10,20,null,30);
+  concat_ws 
+ -----------
+  102030
+ (1 row)
+ 
+ select concat_ws(NULL,10,20,null,30) is null;
+  ?column? 
+ ----------
+  t
+ (1 row)
+ 
+ select reverse('abcde');
+  reverse 
+ ---------
+  edcba
+ (1 row)
+ 
+ select i, left('ahoj', i), right('ahoj', i) from generate_series(-5, 5) t(i) order by i;
+  i  | left | right 
+ ----+------+-------
+  -5 |      | 
+  -4 |      | 
+  -3 | a    | j
+  -2 | ah   | oj
+  -1 | aho  | hoj
+   0 |      | 
+   1 | a    | j
+   2 | ah   | oj
+   3 | aho  | hoj
+   4 | ahoj | ahoj
+   5 | ahoj | ahoj
+ (11 rows)
+ 
diff --git a/src/test/regress/sql/text.sql b/src/test/regress/sql/text.sql
index b739e56..a8768ee 100644
*** a/src/test/regress/sql/text.sql
--- b/src/test/regress/sql/text.sql
*************** select 'four: ' || 2+2;
*** 28,30 ****
--- 28,43 ----
  -- but not this:
  
  select 3 || 4.0;
+ 
+ /*
+  * string functions
+  */
+ select concat('one');
+ select concat(1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws('#','one');
+ select concat_ws('#',1,2,3,'hello',true, false, to_date('20100309','YYYYMMDD'));
+ select concat_ws(',',10,20,null,30);
+ select concat_ws('',10,20,null,30);
+ select concat_ws(NULL,10,20,null,30) is null;
+ select reverse('abcde');
+ select i, left('ahoj', i), right('ahoj', i) from generate_series(-5, 5) t(i) order by i;