| This file is exec.def, from which is created exec.c. |
| It implements the builtin "exec" in Bash. |
| |
| Copyright (C) 1987-2012 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 <http://www.gnu.org/licenses/>. |
| |
| $PRODUCES exec.c |
| |
| $BUILTIN exec |
| $FUNCTION exec_builtin |
| $SHORT_DOC exec [-cl] [-a name] [command [arguments ...]] [redirection ...] |
| Replace the shell with the given command. |
| |
| Execute COMMAND, replacing this shell with the specified program. |
| ARGUMENTS become the arguments to COMMAND. If COMMAND is not specified, |
| any redirections take effect in the current shell. |
| |
| Options: |
| -a name pass NAME as the zeroth argument to COMMAND |
| -c execute COMMAND with an empty environment |
| -l place a dash in the zeroth argument to COMMAND |
| |
| If the command cannot be executed, a non-interactive shell exits, unless |
| the shell option `execfail' is set. |
| |
| Exit Status: |
| Returns success unless COMMAND is not found or a redirection error occurs. |
| $END |
| |
| #include <config.h> |
| |
| #include "../bashtypes.h" |
| #include "posixstat.h" |
| #include <signal.h> |
| #include <errno.h> |
| |
| #if defined (HAVE_UNISTD_H) |
| # include <unistd.h> |
| #endif |
| |
| #include "../bashansi.h" |
| #include "../bashintl.h" |
| |
| #include "../shell.h" |
| #include "../execute_cmd.h" |
| #include "../findcmd.h" |
| #if defined (JOB_CONTROL) |
| # include "../jobs.h" |
| #endif |
| #include "../flags.h" |
| #include "../trap.h" |
| #if defined (HISTORY) |
| # include "../bashhist.h" |
| #endif |
| #include "common.h" |
| #include "bashgetopt.h" |
| |
| /* Not all systems declare ERRNO in errno.h... and some systems #define it! */ |
| #if !defined (errno) |
| extern int errno; |
| #endif /* !errno */ |
| |
| extern int subshell_environment; |
| extern REDIRECT *redirection_undo_list; |
| extern char *exec_argv0; |
| |
| int no_exit_on_failed_exec; |
| |
| /* If the user wants this to look like a login shell, then |
| prepend a `-' onto NAME and return the new name. */ |
| static char * |
| mkdashname (name) |
| char *name; |
| { |
| char *ret; |
| |
| ret = (char *)xmalloc (2 + strlen (name)); |
| ret[0] = '-'; |
| strcpy (ret + 1, name); |
| return ret; |
| } |
| |
| int |
| exec_builtin (list) |
| WORD_LIST *list; |
| { |
| int exit_value = EXECUTION_FAILURE; |
| int cleanenv, login, opt; |
| char *argv0, *command, **args, **env, *newname, *com2; |
| |
| cleanenv = login = 0; |
| exec_argv0 = argv0 = (char *)NULL; |
| |
| reset_internal_getopt (); |
| while ((opt = internal_getopt (list, "cla:")) != -1) |
| { |
| switch (opt) |
| { |
| case 'c': |
| cleanenv = 1; |
| break; |
| case 'l': |
| login = 1; |
| break; |
| case 'a': |
| argv0 = list_optarg; |
| break; |
| default: |
| builtin_usage (); |
| return (EX_USAGE); |
| } |
| } |
| list = loptend; |
| |
| /* First, let the redirections remain. */ |
| dispose_redirects (redirection_undo_list); |
| redirection_undo_list = (REDIRECT *)NULL; |
| |
| if (list == 0) |
| return (EXECUTION_SUCCESS); |
| |
| #if defined (RESTRICTED_SHELL) |
| if (restricted) |
| { |
| sh_restricted ((char *)NULL); |
| return (EXECUTION_FAILURE); |
| } |
| #endif /* RESTRICTED_SHELL */ |
| |
| args = strvec_from_word_list (list, 1, 0, (int *)NULL); |
| |
| /* A command with a slash anywhere in its name is not looked up in $PATH. */ |
| command = absolute_program (args[0]) ? args[0] : search_for_command (args[0], 1); |
| |
| if (command == 0) |
| { |
| if (file_isdir (args[0])) |
| { |
| #if defined (EISDIR) |
| builtin_error (_("%s: cannot execute: %s"), args[0], strerror (EISDIR)); |
| #else |
| builtin_error (_("%s: cannot execute: %s"), args[0], strerror (errno)); |
| #endif |
| exit_value = EX_NOEXEC; |
| } |
| else |
| { |
| sh_notfound (args[0]); |
| exit_value = EX_NOTFOUND; /* As per Posix.2, 3.14.6 */ |
| } |
| goto failed_exec; |
| } |
| |
| com2 = full_pathname (command); |
| if (com2) |
| { |
| if (command != args[0]) |
| free (command); |
| command = com2; |
| } |
| |
| if (argv0) |
| { |
| free (args[0]); |
| args[0] = login ? mkdashname (argv0) : savestring (argv0); |
| exec_argv0 = savestring (args[0]); |
| } |
| else if (login) |
| { |
| newname = mkdashname (args[0]); |
| free (args[0]); |
| args[0] = newname; |
| } |
| |
| /* Decrement SHLVL by 1 so a new shell started here has the same value, |
| preserving the appearance. After we do that, we need to change the |
| exported environment to include the new value. */ |
| if (cleanenv == 0) |
| adjust_shell_level (-1); |
| |
| if (cleanenv) |
| env = (char **)NULL; |
| else |
| { |
| maybe_make_export_env (); |
| env = export_env; |
| } |
| |
| #if defined (HISTORY) |
| if (interactive_shell && subshell_environment == 0) |
| maybe_save_shell_history (); |
| #endif /* HISTORY */ |
| |
| restore_original_signals (); |
| |
| #if defined (JOB_CONTROL) |
| if (subshell_environment == 0) |
| end_job_control (); |
| #endif /* JOB_CONTROL */ |
| |
| exit_value = shell_execve (command, args, env); |
| |
| /* We have to set this to NULL because shell_execve has called realloc() |
| to stuff more items at the front of the array, which may have caused |
| the memory to be freed by realloc(). We don't want to free it twice. */ |
| args = (char **)NULL; |
| if (cleanenv == 0) |
| adjust_shell_level (1); |
| |
| if (exit_value == EX_NOTFOUND) /* no duplicate error message */ |
| goto failed_exec; |
| else if (executable_file (command) == 0) |
| { |
| builtin_error (_("%s: cannot execute: %s"), command, strerror (errno)); |
| exit_value = EX_NOEXEC; /* As per Posix.2, 3.14.6 */ |
| } |
| else |
| file_error (command); |
| |
| failed_exec: |
| FREE (command); |
| |
| if (subshell_environment || (interactive == 0 && no_exit_on_failed_exec == 0)) |
| exit_shell (exit_value); |
| |
| if (args) |
| strvec_dispose (args); |
| |
| initialize_traps (); |
| initialize_signals (1); |
| |
| #if defined (JOB_CONTROL) |
| if (interactive_shell || job_control) |
| restart_job_control (); |
| #endif /* JOB_CONTROL */ |
| |
| return (exit_value); |
| } |