This file is command.def, from which is created command.c. It implements the builtin "command" in Bash. Copyright (C) 1987-2009 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 3 of the License, 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. If not, see . $PRODUCES command.c $BUILTIN command $FUNCTION command_builtin $SHORT_DOC command [-pVv] command [arg ...] Execute a simple command or display information about commands. Runs COMMAND with ARGS suppressing shell function lookup, or display information about the specified COMMANDs. Can be used to invoke commands on disk when a function with the same name exists. Options: -p use a default value for PATH that is guaranteed to find all of the standard utilities -v print a description of COMMAND similar to the `type' builtin -V print a more verbose description of each COMMAND Exit Status: Returns exit status of COMMAND, or failure if COMMAND is not found. $END #include #if defined (HAVE_UNISTD_H) # ifdef _MINIX # include # endif # include #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 defined (RESTRICTED_SHELL) if (use_standard_path && restricted) { sh_restricted ("-p"); return (EXECUTION_FAILURE); } #endif begin_unwind_frame ("command_builtin"); 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); stupidly_hack_special_variables ("PATH"); FREE (standard_path); } 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; } run_unwind_frame ("command_builtin"); return (any_found ? EXECUTION_SUCCESS : EXECUTION_FAILURE); } #define COMMAND_BUILTIN_FLAGS (CMD_NO_FUNCTIONS | CMD_INHIBIT_EXPANSION | CMD_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. */ 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"); stupidly_hack_special_variables ("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 */ }
