pgbench - use enum for meta commands

diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 5d8a01c..6bd3e52 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -373,11 +373,21 @@ typedef enum QueryMode
 static QueryMode querymode = QUERY_SIMPLE;
 static const char *QUERYMODE[] = {"simple", "extended", "prepared"};
 
+typedef enum MetaCommand
+{
+	META_NONE,
+	META_SET,
+	META_SETSHELL,
+	META_SHELL,
+	META_SLEEP
+} MetaCommand;
+
 typedef struct
 {
 	char	   *line;			/* text of command line */
 	int			command_num;	/* unique index of this Command struct */
 	int			type;			/* command type (SQL_COMMAND or META_COMMAND) */
+	MetaCommand meta;			/* meta command identifier, if appropriate */
 	int			argc;			/* number of command words */
 	char	   *argv[MAX_ARGS]; /* command word list */
 	PgBenchExpr *expr;			/* parsed expression, if needed */
@@ -1721,6 +1731,26 @@ evaluateExpr(TState *thread, CState *st, PgBenchExpr *expr, PgBenchValue *retval
 	}
 }
 
+/* return meta-command enum identifier */
+static MetaCommand
+getMetaCommand(const char * cmd)
+{
+	MetaCommand mc;
+	if (cmd == NULL)
+		mc = META_NONE;
+	else if (pg_strcasecmp(cmd, "set") == 0)
+		mc = META_SET;
+	else if (pg_strcasecmp(cmd, "setshell") == 0)
+		mc = META_SETSHELL;
+	else if (pg_strcasecmp(cmd, "shell") == 0)
+		mc = META_SHELL;
+	else if (pg_strcasecmp(cmd, "sleep") == 0)
+		mc = META_SLEEP;
+	else
+		mc = META_NONE;
+	return mc;
+}
+
 /*
  * Run a shell command. The result is assigned to the variable if not NULL.
  * Return true if succeeded, or false on error.
@@ -2214,7 +2244,7 @@ doCustom(TState *thread, CState *st, StatsData *agg)
 						fprintf(stderr, "\n");
 					}
 
-					if (pg_strcasecmp(argv[0], "sleep") == 0)
+					if (command->meta == META_SLEEP)
 					{
 						/*
 						 * A \sleep doesn't execute anything, we just get the
@@ -2240,7 +2270,7 @@ doCustom(TState *thread, CState *st, StatsData *agg)
 					}
 					else
 					{
-						if (pg_strcasecmp(argv[0], "set") == 0)
+						if (command->meta == META_SET)
 						{
 							PgBenchExpr *expr = command->expr;
 							PgBenchValue result;
@@ -2259,7 +2289,7 @@ doCustom(TState *thread, CState *st, StatsData *agg)
 								break;
 							}
 						}
-						else if (pg_strcasecmp(argv[0], "setshell") == 0)
+						else if (command->meta == META_SETSHELL)
 						{
 							bool		ret = runShellCommand(st, argv[1], argv + 2, argc - 2);
 
@@ -2279,7 +2309,7 @@ doCustom(TState *thread, CState *st, StatsData *agg)
 								/* succeeded */
 							}
 						}
-						else if (pg_strcasecmp(argv[0], "shell") == 0)
+						else if (command->meta == META_SHELL)
 						{
 							bool		ret = runShellCommand(st, NULL, argv + 1, argc - 1);
 
@@ -3023,6 +3053,7 @@ process_sql_command(PQExpBuffer buf, const char *source)
 	my_command = (Command *) pg_malloc0(sizeof(Command));
 	my_command->command_num = num_commands++;
 	my_command->type = SQL_COMMAND;
+	my_command->meta = META_NONE;
 	initSimpleStats(&my_command->stats);
 
 	/*
@@ -3091,7 +3122,9 @@ process_backslash_command(PsqlScanState sstate, const char *source)
 	my_command->argv[j++] = pg_strdup(word_buf.data);
 	my_command->argc++;
 
-	if (pg_strcasecmp(my_command->argv[0], "set") == 0)
+	my_command->meta = getMetaCommand(my_command->argv[0]);
+
+	if (my_command->meta == META_SET)
 	{
 		/* For \set, collect var name, then lex the expression. */
 		yyscan_t	yyscanner;
@@ -3146,7 +3179,7 @@ process_backslash_command(PsqlScanState sstate, const char *source)
 												  expr_scanner_offset(sstate),
 												  true);
 
-	if (pg_strcasecmp(my_command->argv[0], "sleep") == 0)
+	if (my_command->meta == META_SLEEP)
 	{
 		if (my_command->argc < 2)
 			syntax_error(source, lineno, my_command->line, my_command->argv[0],
@@ -3187,13 +3220,13 @@ process_backslash_command(PsqlScanState sstate, const char *source)
 							 my_command->argv[2], offsets[2] - start_offset);
 		}
 	}
-	else if (pg_strcasecmp(my_command->argv[0], "setshell") == 0)
+	else if (my_command->meta == META_SETSHELL)
 	{
 		if (my_command->argc < 3)
 			syntax_error(source, lineno, my_command->line, my_command->argv[0],
 						 "missing argument", NULL, -1);
 	}
-	else if (pg_strcasecmp(my_command->argv[0], "shell") == 0)
+	else if (my_command->meta == META_SHELL)
 	{
 		if (my_command->argc < 2)
 			syntax_error(source, lineno, my_command->line, my_command->argv[0],
@@ -3201,6 +3234,7 @@ process_backslash_command(PsqlScanState sstate, const char *source)
 	}
 	else
 	{
+		/* my_command->meta == META_NONE */
 		syntax_error(source, lineno, my_command->line, my_command->argv[0],
 					 "invalid command", NULL, -1);
 	}