1 /* Creation of autonomous subprocesses.
2 Copyright (C) 2001-2004, 2006-2009 Free Software Foundation, Inc.
3 Written by Bruno Haible <haible@clisp.cons.org>, 2001.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
32 #include "fatal-signal.h"
33 #include "wait-process.h"
36 #define _(str) gettext (str)
38 #if defined _MSC_VER || defined __MINGW32__
40 /* Native Woe32 API. */
42 # include "w32spawn.h"
57 /* The results of open() in this file are not used with fchdir,
58 therefore save some unnecessary work in fchdir.c. */
65 /* EINTR handling for close(), open().
66 These functions can return -1/EINTR even though we don't have any
67 signal handlers set up, namely when we get interrupted via SIGSTOP. */
70 nonintr_close (int fd)
76 while (retval < 0 && errno == EINTR);
80 #define close nonintr_close
83 nonintr_open (const char *pathname, int oflag, mode_t mode)
88 retval = open (pathname, oflag, mode);
89 while (retval < 0 && errno == EINTR);
93 #undef open /* avoid warning on VMS */
94 #define open nonintr_open
99 /* Execute a command, optionally redirecting any of the three standard file
100 descriptors to /dev/null. Return its exit code.
101 If it didn't terminate correctly, exit if exit_on_error is true, otherwise
103 If slave_process is true, the child process will be terminated when its
104 creator receives a catchable fatal signal. */
106 execute (const char *progname,
107 const char *prog_path, char **prog_argv,
109 bool null_stdin, bool null_stdout, bool null_stderr,
110 bool slave_process, bool exit_on_error,
113 #if defined _MSC_VER || defined __MINGW32__
115 /* Native Woe32 API. */
123 /* FIXME: Need to free memory allocated by prepare_spawn. */
124 prog_argv = prepare_spawn (prog_argv);
126 /* Save standard file handles of parent process. */
128 orig_stdin = dup_noinherit (STDIN_FILENO);
130 orig_stdout = dup_noinherit (STDOUT_FILENO);
132 orig_stderr = dup_noinherit (STDERR_FILENO);
135 /* Create standard file handles of child process. */
139 || ((nullinfd = open ("NUL", O_RDONLY, 0)) >= 0
140 && (nullinfd == STDIN_FILENO
141 || (dup2 (nullinfd, STDIN_FILENO) >= 0
142 && close (nullinfd) >= 0))))
143 && (!(null_stdout || null_stderr)
144 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
146 || nulloutfd == STDOUT_FILENO
147 || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
149 || nulloutfd == STDERR_FILENO
150 || dup2 (nulloutfd, STDERR_FILENO) >= 0)
151 && ((null_stdout && nulloutfd == STDOUT_FILENO)
152 || (null_stderr && nulloutfd == STDERR_FILENO)
153 || close (nulloutfd) >= 0))))
154 /* Use spawnvpe and pass the environment explicitly. This is needed if
155 the program has modified the environment using putenv() or [un]setenv().
156 On Windows, programs have two environments, one in the "environment
157 block" of the process and managed through SetEnvironmentVariable(), and
158 one inside the process, in the location retrieved by the 'environ'
159 macro. When using spawnvp() without 'e', the child process inherits a
160 copy of the environment block - ignoring the effects of putenv() and
163 exitcode = spawnvpe (P_WAIT, prog_path, prog_argv, environ);
164 if (exitcode < 0 && errno == ENOEXEC)
166 /* prog is not an native executable. Try to execute it as a
167 shell script. Note that prepare_spawn() has already prepended
168 a hidden element "sh.exe" to prog_argv. */
170 exitcode = spawnvpe (P_WAIT, prog_argv[0], prog_argv, environ);
178 /* Restore standard file handles of parent process. */
180 dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
182 dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
184 dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
186 if (termsigp != NULL)
191 if (exit_on_error || !null_stderr)
192 error (exit_on_error ? EXIT_FAILURE : 0, errno,
193 _("%s subprocess failed"), progname);
202 /* Note about 127: Some errors during posix_spawnp() cause the function
203 posix_spawnp() to return an error code; some other errors cause the
204 subprocess to exit with return code 127. It is implementation
205 dependent which error is reported which way. We treat both cases as
208 sigset_t blocked_signals;
209 posix_spawn_file_actions_t actions;
210 bool actions_allocated;
211 posix_spawnattr_t attrs;
212 bool attrs_allocated;
222 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
223 block_fatal_signals ();
225 actions_allocated = false;
226 attrs_allocated = false;
227 if ((err = posix_spawn_file_actions_init (&actions)) != 0
228 || (actions_allocated = true,
230 && (err = posix_spawn_file_actions_addopen (&actions,
232 "/dev/null", O_RDONLY,
236 && (err = posix_spawn_file_actions_addopen (&actions,
242 && (err = posix_spawn_file_actions_addopen (&actions,
248 && ((err = posix_spawnattr_init (&attrs)) != 0
249 || (attrs_allocated = true,
250 (err = posix_spawnattr_setsigmask (&attrs,
253 || (err = posix_spawnattr_setflags (&attrs,
254 POSIX_SPAWN_SETSIGMASK))
256 || (err = posix_spawnp (&child, prog_path, &actions,
257 attrs_allocated ? &attrs : NULL, prog_argv,
261 if (actions_allocated)
262 posix_spawn_file_actions_destroy (&actions);
264 posix_spawnattr_destroy (&attrs);
266 unblock_fatal_signals ();
267 if (termsigp != NULL)
269 if (exit_on_error || !null_stderr)
270 error (exit_on_error ? EXIT_FAILURE : 0, err,
271 _("%s subprocess failed"), progname);
274 posix_spawn_file_actions_destroy (&actions);
276 posix_spawnattr_destroy (&attrs);
279 block_fatal_signals ();
280 /* Use vfork() instead of fork() for efficiency. */
281 if ((child = vfork ()) == 0)
283 /* Child process code. */
288 || ((nullinfd = open ("/dev/null", O_RDONLY, 0)) >= 0
289 && (nullinfd == STDIN_FILENO
290 || (dup2 (nullinfd, STDIN_FILENO) >= 0
291 && close (nullinfd) >= 0))))
292 && (!(null_stdout || null_stderr)
293 || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
295 || nulloutfd == STDOUT_FILENO
296 || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
298 || nulloutfd == STDERR_FILENO
299 || dup2 (nulloutfd, STDERR_FILENO) >= 0)
300 && ((null_stdout && nulloutfd == STDOUT_FILENO)
301 || (null_stderr && nulloutfd == STDERR_FILENO)
302 || close (nulloutfd) >= 0)))
303 && (!slave_process || (unblock_fatal_signals (), true)))
304 execvp (prog_path, prog_argv);
310 unblock_fatal_signals ();
311 if (termsigp != NULL)
313 if (exit_on_error || !null_stderr)
314 error (exit_on_error ? EXIT_FAILURE : 0, errno,
315 _("%s subprocess failed"), progname);
321 register_slave_subprocess (child);
322 unblock_fatal_signals ();
325 return wait_subprocess (child, progname, ignore_sigpipe, null_stderr,
326 slave_process, exit_on_error, termsigp);