This file is command.def, from which is created command.c.
It implements the builtin "command" in Bash.
Copyright (C) 1987-2004 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
Bash is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.
$PRODUCES command.c
$BUILTIN command
$FUNCTION command_builtin
$SHORT_DOC command [-pVv] command [arg ...]
Runs COMMAND with ARGS ignoring shell functions. If you have a shell
function called `ls', and you wish to call the command `ls', you can
say "command ls". If the -p option is given, a default value is used
for PATH that is guaranteed to find all of the standard utilities. If
the -V or -v option is given, a string is printed describing COMMAND.
The -V option produces a more verbose description.
$END
#include <config.h>
#if defined (HAVE_UNISTD_H)
# ifdef _MINIX
# include <sys/types.h>
# endif
# include <unistd.h>
#endif
#include "../bashansi.h"
#include "../shell.h"
#include "../execute_cmd.h"
#include "../flags.h"
#include "bashgetopt.h"
#include "common.h"
#if defined (_CS_PATH) && defined (HAVE_CONFSTR) && !HAVE_DECL_CONFSTR
extern size_t confstr __P((int, char *, size_t));
#endif
extern int subshell_environment;
static void restore_path __P((char *));
static char *get_standard_path __P((void));
/* Run the commands mentioned in LIST without paying attention to shell
functions. */
int
command_builtin (list)
WORD_LIST *list;
{
int result, verbose, use_standard_path, opt;
char *old_path, *standard_path;
COMMAND *command;
verbose = use_standard_path = 0;
reset_internal_getopt ();
while ((opt = internal_getopt (list, "pvV")) != -1)
{
switch (opt)
{
case 'p':
use_standard_path = 1;
break;
case 'V':
verbose = CDESC_SHORTDESC|CDESC_ABSPATH; /* look in common.h for constants */
break;
case 'v':
verbose = CDESC_REUSABLE; /* ditto */
break;
default:
builtin_usage ();
return (EX_USAGE);
}
}
list = loptend;
if (list == 0)
return (EXECUTION_SUCCESS);
if (verbose)
{
int found, any_found;
for (any_found = 0; list; list = list->next)
{
found = describe_command (list->word->word, verbose);
if (found == 0 && verbose != CDESC_REUSABLE)
sh_notfound (list->word->word);
any_found += found;
}
return (any_found ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
}
#if defined (RESTRICTED_SHELL)
if (use_standard_path && restricted)
{
sh_restricted ("-p");
return (EXECUTION_FAILURE);
}
#endif
begin_unwind_frame ("command_builtin");
/* We don't want this to be reparsed (consider command echo 'foo &'), so
just make a simple_command structure and call execute_command with it. */
if (use_standard_path)
{
old_path = get_string_value ("PATH");
/* If old_path is NULL, $PATH is unset. If so, we want to make sure
it's unset after this command completes. */
if (old_path)
old_path = savestring (old_path);
add_unwind_protect ((Function *)restore_path, old_path);
standard_path = get_standard_path ();
bind_variable ("PATH", standard_path ? standard_path : "", 0);
FREE (standard_path);
}
#define COMMAND_BUILTIN_FLAGS (CMD_NO_FUNCTIONS | CMD_INHIBIT_EXPANSION | CMD_COMMAND_BUILTIN)
command = make_bare_simple_command ();
command->value.Simple->words = (WORD_LIST *)copy_word_list (list);
command->value.Simple->redirects = (REDIRECT *)NULL;
command->flags |= COMMAND_BUILTIN_FLAGS;
command->value.Simple->flags |= COMMAND_BUILTIN_FLAGS;
#if 0
/* This breaks for things like ( cd /tmp ; command z ababa ; echo next )
or $(command echo a ; command echo b;) or even
{ command echo a; command echo b; } & */
/* If we're in a subshell, see if we can get away without forking
again, since we've already forked to run this builtin. */
if (subshell_environment)
{
command->flags |= CMD_NO_FORK;
command->value.Simple->flags |= CMD_NO_FORK;
}
#endif
add_unwind_protect ((char *)dispose_command, command);
result = execute_command (command);
run_unwind_frame ("command_builtin");
return (result);
}
/* Restore the value of the $PATH variable after replacing it when
executing `command -p'. */
static void
restore_path (var)
char *var;
{
if (var)
{
bind_variable ("PATH", var, 0);
free (var);
}
else
unbind_variable ("PATH");
}
/* Return a value for PATH that is guaranteed to find all of the standard
utilities. This uses Posix.2 configuration variables, if present. It
uses a value defined in config.h as a last resort. */
static char *
get_standard_path ()
{
#if defined (_CS_PATH) && defined (HAVE_CONFSTR)
char *p;
size_t len;
len = (size_t)confstr (_CS_PATH, (char *)NULL, (size_t)0);
if (len > 0)
{
p = (char *)xmalloc (len + 2);
*p = '\0';
confstr (_CS_PATH, p, len);
return (p);
}
else
return (savestring (STANDARD_UTILS_PATH));
#else /* !_CS_PATH || !HAVE_CONFSTR */
# if defined (CS_PATH)
return (savestring (CS_PATH));
# else
return (savestring (STANDARD_UTILS_PATH));
# endif /* !CS_PATH */
#endif /* !_CS_PATH || !HAVE_CONFSTR */
}