psql \h alter scrolls of screen

Started by Bruce Momjianover 22 years ago6 messages
#1Bruce Momjian
pgman@candle.pha.pa.us

When I do '\h alter' in psql, the content scrolls off my screen.

Should we be using the pager for \h output?

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
#2Robert Treat
xzilla@users.sourceforge.net
In reply to: Bruce Momjian (#1)
Re: psql \h alter scrolls of screen

On Thu, 2003-09-04 at 21:14, Bruce Momjian wrote:

When I do '\h alter' in psql, the content scrolls off my screen.

i think you need a bigger screen

Should we be using the pager for \h output?

in 7.3.4 we do, let me check 7.4...seems to work, though I am on beta1
on this box.

Robert Treat
--
Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL

#3Tom Lane
tgl@sss.pgh.pa.us
In reply to: Robert Treat (#2)
Re: psql \h alter scrolls of screen

Robert Treat <xzilla@users.sourceforge.net> writes:

On Thu, 2003-09-04 at 21:14, Bruce Momjian wrote:

Should we be using the pager for \h output?

in 7.3.4 we do, let me check 7.4...seems to work, though I am on beta1
on this box.

Hmm. I do not see the pager used for \h in either version, though it
does get used for \? ...

regards, tom lane

#4Bruce Momjian
pgman@candle.pha.pa.us
In reply to: Tom Lane (#3)
1 attachment(s)
Re: [HACKERS] psql \h alter scrolls of screen

Tom Lane wrote:

Robert Treat <xzilla@users.sourceforge.net> writes:

On Thu, 2003-09-04 at 21:14, Bruce Momjian wrote:

Should we be using the pager for \h output?

in 7.3.4 we do, let me check 7.4...seems to work, though I am on beta1
on this box.

Hmm. I do not see the pager used for \h in either version, though it
does get used for \? ...

OK, turns out the '\h alter' code does a simple printf(), not a
PageOutput() and fprintf() to that pipe. Various \h outputs are long,
including CREATE TABLE, GRANT, and ALTER TABLE. ALTER itself is really
larger because it prints all the ALTER commands help.

The attached patch counts the number of newlines output by \h command,
and invokes the pager where appropriate.

This isn't a bug fix, so it will be kept for 7.5.

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Attachments:

/pgpatches/help_pagertext/plainDownload
Index: src/bin/psql/help.c
===================================================================
RCS file: /cvsroot/pgsql-server/src/bin/psql/help.c,v
retrieving revision 1.78
diff -c -c -r1.78 help.c
*** src/bin/psql/help.c	10 Sep 2003 21:35:55 -0000	1.78
--- src/bin/psql/help.c	10 Sep 2003 22:12:39 -0000
***************
*** 303,322 ****
  	{
  		int			i;
  		bool		help_found = false;
  		size_t		len;
! 
  		/* don't care about trailing spaces */
  		len = strlen(topic);
  		while (topic[len - 1] == ' ')
  			len--;
  
  		for (i = 0; QL_HELP[i].cmd; i++)
  		{
  			if (strncasecmp(topic, QL_HELP[i].cmd, len) == 0 ||
  				strcmp(topic, "*") == 0)
  			{
  				help_found = true;
! 				printf(_("Command:     %s\n"
  						 "Description: %s\n"
  						 "Syntax:\n%s\n\n"),
  					 QL_HELP[i].cmd, QL_HELP[i].help, QL_HELP[i].syntax);
--- 303,343 ----
  	{
  		int			i;
  		bool		help_found = false;
+ 		FILE	   *output;
  		size_t		len;
! 		int			nl_count = 0;
! 		char		*ch;
! 		
  		/* don't care about trailing spaces */
  		len = strlen(topic);
  		while (topic[len - 1] == ' ')
  			len--;
  
+ 		/* Count newlines for pager */
+ 		for (i = 0; QL_HELP[i].cmd; i++)
+ 		{
+ 			if (strncasecmp(topic, QL_HELP[i].cmd, len) == 0 ||
+ 				strcmp(topic, "*") == 0)
+ 			{
+ 				nl_count += 5;
+ 				for (ch = QL_HELP[i].syntax; *ch != '\0'; ch++)
+ 					if (*ch == '\n')
+ 						nl_count++;
+ 				/* If we have an exact match, exit.  Fixes \h SELECT */
+ 				if (strcasecmp(topic, QL_HELP[i].cmd) == 0)
+ 					break;
+ 			}
+ 		}
+ 
+ 		output = PageOutput(nl_count, pager);
+ 
  		for (i = 0; QL_HELP[i].cmd; i++)
  		{
  			if (strncasecmp(topic, QL_HELP[i].cmd, len) == 0 ||
  				strcmp(topic, "*") == 0)
  			{
  				help_found = true;
! 				fprintf(output, _("Command:     %s\n"
  						 "Description: %s\n"
  						 "Syntax:\n%s\n\n"),
  					 QL_HELP[i].cmd, QL_HELP[i].help, QL_HELP[i].syntax);
***************
*** 327,333 ****
  		}
  
  		if (!help_found)
! 			printf(_("No help available for \"%-.*s\".\nTry \\h with no arguments to see available help.\n"), (int) len, topic);
  	}
  }
  
--- 348,363 ----
  		}
  
  		if (!help_found)
! 			fprintf(output, _("No help available for \"%-.*s\".\nTry \\h with no arguments to see available help.\n"), (int) len, topic);
! 
! 		/* Only close if we used the pager */
! 		if (output != stdout)
! 		{
! 			pclose(output);
! #ifndef WIN32
! 			pqsignal(SIGPIPE, SIG_DFL);
! #endif
! 		}
  	}
  }
  
#5Peter Eisentraut
peter_e@gmx.net
In reply to: Bruce Momjian (#4)
Re: [HACKERS] psql \h alter scrolls of screen

Bruce Momjian writes:

OK, turns out the '\h alter' code does a simple printf(), not a
PageOutput() and fprintf() to that pipe. Various \h outputs are long,
including CREATE TABLE, GRANT, and ALTER TABLE. ALTER itself is really
larger because it prints all the ALTER commands help.

They are long, but not not longer than a few pages, in which case it's
more convenient to use your terminals scrolling functionality. It's a
different story when query output is thousands of lines long, in which
case you usually cannot scroll anymore.

--
Peter Eisentraut peter_e@gmx.net

#6Bruce Momjian
pgman@candle.pha.pa.us
In reply to: Peter Eisentraut (#5)
Re: [HACKERS] psql \h alter scrolls of screen

Peter Eisentraut wrote:

Bruce Momjian writes:

OK, turns out the '\h alter' code does a simple printf(), not a
PageOutput() and fprintf() to that pipe. Various \h outputs are long,
including CREATE TABLE, GRANT, and ALTER TABLE. ALTER itself is really
larger because it prints all the ALTER commands help.

They are long, but not not longer than a few pages, in which case it's
more convenient to use your terminals scrolling functionality. It's a
different story when query output is thousands of lines long, in which
case you usually cannot scroll anymore.

Yes, but our table output already pages if it exceeds the screen size,
so it seems we should be consistent, and if someone is on the console,
they might not have scroll-back, and are left with ^S, ^Q. :-)

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073