From 4a87c9895dd35426d872466b8313bc45e7e2867e Mon Sep 17 00:00:00 2001
From: axel <axel@liljencrantz.se>
Date: Thu, 13 Jul 2006 03:46:55 +1000
Subject: [PATCH] Add -q/--query switch to the functions builtin. Works just
 like the same switch to set does. Useful for checking for the existance of
 functions in a script

darcs-hash:20060712174655-ac50b-14a98a15751bb5ddddf4ffb41521b616bef5e40c.gz
---
 builtin.c                        | 43 +++++++++++++++++++++-----------
 doc_src/functions.txt            | 15 +++++++----
 share/completions/functions.fish |  2 +-
 3 files changed, 40 insertions(+), 20 deletions(-)

diff --git a/builtin.c b/builtin.c
index 4b30dce07..a46fa6383 100644
--- a/builtin.c
+++ b/builtin.c
@@ -774,6 +774,7 @@ static int builtin_functions( wchar_t **argv )
 	int list=0;
 	int show_hidden=0;
 	int res = 0;
+	int query = 0;
 
 	woptind=0;
 
@@ -800,6 +801,10 @@ static int builtin_functions( wchar_t **argv )
 				L"help", no_argument, 0, 'h'
 			}
 			,
+			{
+				L"query", no_argument, 0, 'q'
+			}
+			,
 			{
 				0, 0, 0, 0
 			}
@@ -812,7 +817,7 @@ static int builtin_functions( wchar_t **argv )
 
 		int opt = wgetopt_long( argc,
 								argv,
-								L"ed:nah",
+								L"ed:nahq",
 								long_options,
 								&opt_index );
 		if( opt == -1 )
@@ -852,6 +857,10 @@ static int builtin_functions( wchar_t **argv )
 				builtin_print_help( argv[0], sb_out );
 				return 0;
 
+			case 'q':
+				query = 1;
+				break;
+
 			case '?':
 				builtin_print_help( argv[0], sb_err );
 
@@ -862,9 +871,9 @@ static int builtin_functions( wchar_t **argv )
 	}
 
 	/*
-	  Erase, desc and list are mutually exclusive
+	  Erase, desc, query and list are mutually exclusive
 	*/
-	if( (erase + (desc!=0) + list) > 1 )
+	if( (erase + (desc!=0) + list + query) > 1 )
 	{
 		sb_printf( sb_err,
 				   _( L"%ls: Invalid combination of options\n" ),
@@ -951,22 +960,25 @@ static int builtin_functions( wchar_t **argv )
 		return 0;
 	}
 
-
 	switch( argc - woptind )
 	{
 		case 0:
 		{
-			sb_append( sb_out, _( L"Current function definitions are:\n\n" ) );
-			al_init( &names );
-			function_get_names( &names, show_hidden );
-			sort_list( &names );
-			
-			for( i=0; i<al_get_count( &names ); i++ )
+			if( !query )
 			{
-				functions_def( (wchar_t *)al_get( &names, i ) );
+				sb_append( sb_out, _( L"Current function definitions are:\n\n" ) );
+				al_init( &names );
+				function_get_names( &names, show_hidden );
+				sort_list( &names );
+				
+				for( i=0; i<al_get_count( &names ); i++ )
+				{
+					functions_def( (wchar_t *)al_get( &names, i ) );
+				}
+				
+				al_destroy( &names );
 			}
 			
-			al_destroy( &names );
 			break;
 		}
 
@@ -978,8 +990,11 @@ static int builtin_functions( wchar_t **argv )
 					res++;
 				else
 				{
-					functions_def( argv[i] );
-				}
+					if( !query )
+					{
+						functions_def( argv[i] );
+					}
+				}				
 			}
 
 			break;
diff --git a/doc_src/functions.txt b/doc_src/functions.txt
index 9def57910..642947821 100644
--- a/doc_src/functions.txt
+++ b/doc_src/functions.txt
@@ -12,11 +12,16 @@ This builtin command is used to print or erase functions.
 - <code>-e</code> or <code>--erase</code> causes the specified functions to be erased.
 - <code>-h</code> or <code>--help</code> display a help message and exit
 - <code>-n</code> or <code>--names</code> list only the names of all defined functions
+- <code>-q</code> or <code>--query</code> test if the specified functions exist. Does not output anything, but the builtins exit status is the number of functions specified that were not defined.
 
-If \c functions is called with no arguments, the names and definition
-of all functions are printed, otherwise, the specified function
-definitions will be printed.
+The default behavior of \c functions when called with no arguments,
+is to print the names and definitions of all defined functions. If any
+non-switch parameters are given, only the definition of the specified
+functions are printed. 
 
-If a function is automatically loaded, using <code>functions -e</code>
-to erase it will not remove the function.
+Automatically loaded functions can not be removed using functions
+-e. Either remove the definition file or change the
+$fish_function_path variable to remove autoloaded functions.
 
+The exit status of the functions builtin is the number functions
+specified in the argument list that do not exist.
diff --git a/share/completions/functions.fish b/share/completions/functions.fish
index 8f5442026..e614ed39f 100644
--- a/share/completions/functions.fish
+++ b/share/completions/functions.fish
@@ -3,4 +3,4 @@ complete -c functions -xa "(functions -na)" -d (N_ "Function")
 complete -c functions -s a -l all -d (N_ "Show hidden functions")
 complete -c functions -s h -l help -d (N_ "Display help and exit")
 complete -c functions -s d -l description -d (N_ "Set function description") -x
-
+complete -c functions -s q -l query -d (N_ "Test if function is defined")