builtins/command.def

   1 This file is command.def, from which is created command.c.
   2 It implements the builtin "command" in Bash.
   3
   4 Copyright (C) 1987-2015 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Bash, the Bourne Again SHell.
   7
   8 Bash is free software: you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation, either version 3 of the License, or
  11 (at your option) any later version.
  12
  13 Bash is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 $PRODUCES command.c
  22
  23 $BUILTIN command
  24 $FUNCTION command_builtin
  25 $SHORT_DOC command [-pVv] command [arg ...]
  26 Execute a simple command or display information about commands.
  27
  28 Runs COMMAND with ARGS suppressing  shell function lookup, or display
  29 information about the specified COMMANDs.  Can be used to invoke commands
  30 on disk when a function with the same name exists.
  31
  32 Options:
  33   -p    use a default value for PATH that is guaranteed to find all of
  34         the standard utilities
  35   -v    print a description of COMMAND similar to the `type' builtin
  36   -V    print a more verbose description of each COMMAND
  37
  38 Exit Status:
  39 Returns exit status of COMMAND, or failure if COMMAND is not found.
  40 $END
  41
  42 #include <config.h>
  43
  44 #if defined (HAVE_UNISTD_H)
  45 #  ifdef _MINIX
  46 #    include <sys/types.h>
  47 #  endif
  48 #  include <unistd.h>
  49 #endif
  50
  51 #include "../bashansi.h"
  52
  53 #include "../shell.h"
  54 #include "../execute_cmd.h"
  55 #include "../flags.h"
  56 #include "bashgetopt.h"
  57 #include "common.h"
  58
  59 #if defined (_CS_PATH) && defined (HAVE_CONFSTR) && !HAVE_DECL_CONFSTR
  60 extern size_t confstr __P((int, char *, size_t));
  61 #endif
  62
  63 /* Run the commands mentioned in LIST without paying attention to shell
  64    functions. */
  65 int
  66 command_builtin (list)
  67      WORD_LIST *list;
  68 {
  69   int result, verbose, use_standard_path, opt;
  70   COMMAND *command;
  71
  72   verbose = use_standard_path = 0;
  73   reset_internal_getopt ();
  74   while ((opt = internal_getopt (list, "pvV")) != -1)
  75     {
  76       switch (opt)
  77         {
  78         case 'p':
  79           use_standard_path = CDESC_STDPATH;
  80           break;
  81         case 'V':
  82           verbose = CDESC_SHORTDESC|CDESC_ABSPATH;      /* look in common.h for constants */
  83           break;
  84         case 'v':
  85           verbose = CDESC_REUSABLE;     /* ditto */
  86           break;
  87         CASE_HELPOPT;
  88         default:
  89           builtin_usage ();
  90           return (EX_USAGE);
  91         }
  92     }
  93   list = loptend;
  94
  95   if (list == 0)
  96     return (EXECUTION_SUCCESS);
  97
  98 #if defined (RESTRICTED_SHELL)
  99   if (use_standard_path && restricted)
 100     {
 101       sh_restricted ("-p");
 102       return (EXECUTION_FAILURE);
 103     }
 104 #endif
 105
 106   if (verbose)
 107     {
 108       int found, any_found;
 109
 110       for (any_found = 0; list; list = list->next)
 111         {
 112           found = describe_command (list->word->word, verbose|use_standard_path);
 113
 114           if (found == 0 && verbose != CDESC_REUSABLE)
 115             sh_notfound (list->word->word);
 116
 117           any_found += found;
 118         }
 119
 120       return (any_found ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
 121     }
 122
 123   begin_unwind_frame ("command_builtin");
 124
 125 #define COMMAND_BUILTIN_FLAGS (CMD_NO_FUNCTIONS | CMD_INHIBIT_EXPANSION | CMD_COMMAND_BUILTIN | (use_standard_path ? CMD_STDPATH : 0))
 126
 127   /* We don't want this to be reparsed (consider command echo 'foo &'), so
 128      just make a simple_command structure and call execute_command with it. */
 129   command = make_bare_simple_command ();
 130   command->value.Simple->words = (WORD_LIST *)copy_word_list (list);
 131   command->value.Simple->redirects = (REDIRECT *)NULL;
 132   command->flags |= COMMAND_BUILTIN_FLAGS;
 133   command->value.Simple->flags |= COMMAND_BUILTIN_FLAGS;
 134
 135   add_unwind_protect ((char *)dispose_command, command);
 136   result = execute_command (command);
 137
 138   run_unwind_frame ("command_builtin");
 139
 140   return (result);
 141 }