1 /* Creation of autonomous subprocesses.
2 Copyright (C) 2001-2004, 2006-2015 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 _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
40 /* Native Windows API. */
42 # include "w32spawn.h"
51 /* environ is the exported symbol referencing the internal
52 __cygwin_environ variable on cygwin64:
53 <https://cygwin.com/ml/cygwin/2013-06/msg00228.html>. */
54 #if defined __CYGWIN__ && defined __x86_64__
55 extern DLL_VARIABLE char **environ;
59 #if defined EINTR && ((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__)
61 /* EINTR handling for close(), open().
62 These functions can return -1/EINTR even though we don't have any
63 signal handlers set up, namely when we get interrupted via SIGSTOP. */
66 nonintr_close (int fd)
72 while (retval < 0 && errno == EINTR);
76 #define close nonintr_close
79 nonintr_open (const char *pathname, int oflag, mode_t mode)
84 retval = open (pathname, oflag, mode);
85 while (retval < 0 && errno == EINTR);
89 #undef open /* avoid warning on VMS */
90 #define open nonintr_open
95 /* Execute a command, optionally redirecting any of the three standard file
96 descriptors to /dev/null. Return its exit code.
97 If it didn't terminate correctly, exit if exit_on_error is true, otherwise
99 If slave_process is true, the child process will be terminated when its
100 creator receives a catchable fatal signal. */
102 execute (const char *progname,
103 const char *prog_path, char **prog_argv,
105 bool null_stdin, bool null_stdout, bool null_stderr,
106 bool slave_process, bool exit_on_error,
109 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
111 /* Native Windows API. */
119 /* FIXME: Need to free memory allocated by prepare_spawn. */
120 prog_argv = prepare_spawn (prog_argv);
122 /* Save standard file handles of parent process. */
124 orig_stdin = dup_safer_noinherit (STDIN_FILENO);
126 orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
128 orig_stderr = dup_safer_noinherit (STDERR_FILENO);
131 /* Create standard file handles of child process. */
135 || ((nullinfd = open ("NUL", O_RDONLY, 0)) >= 0
136 && (nullinfd == STDIN_FILENO
137 || (dup2 (nullinfd, STDIN_FILENO) >= 0
138 && close (nullinfd) >= 0))))
139 && (!(null_stdout || null_stderr)
140 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
142 || nulloutfd == STDOUT_FILENO
143 || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
145 || nulloutfd == STDERR_FILENO
146 || dup2 (nulloutfd, STDERR_FILENO) >= 0)
147 && ((null_stdout && nulloutfd == STDOUT_FILENO)
148 || (null_stderr && nulloutfd == STDERR_FILENO)
149 || close (nulloutfd) >= 0))))
150 /* Use spawnvpe and pass the environment explicitly. This is needed if
151 the program has modified the environment using putenv() or [un]setenv().
152 On Windows, programs have two environments, one in the "environment
153 block" of the process and managed through SetEnvironmentVariable(), and
154 one inside the process, in the location retrieved by the 'environ'
155 macro. When using spawnvp() without 'e', the child process inherits a
156 copy of the environment block - ignoring the effects of putenv() and
159 exitcode = spawnvpe (P_WAIT, prog_path, (const char **) prog_argv,
160 (const char **) environ);
161 if (exitcode < 0 && errno == ENOEXEC)
163 /* prog is not a native executable. Try to execute it as a
164 shell script. Note that prepare_spawn() has already prepended
165 a hidden element "sh.exe" to prog_argv. */
167 exitcode = spawnvpe (P_WAIT, prog_argv[0], (const char **) prog_argv,
168 (const char **) environ);
176 /* Restore standard file handles of parent process. */
178 undup_safer_noinherit (orig_stderr, STDERR_FILENO);
180 undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
182 undup_safer_noinherit (orig_stdin, STDIN_FILENO);
184 if (termsigp != NULL)
189 if (exit_on_error || !null_stderr)
190 error (exit_on_error ? EXIT_FAILURE : 0, errno,
191 _("%s subprocess failed"), progname);
200 /* Note about 127: Some errors during posix_spawnp() cause the function
201 posix_spawnp() to return an error code; some other errors cause the
202 subprocess to exit with return code 127. It is implementation
203 dependent which error is reported which way. We treat both cases as
205 sigset_t blocked_signals;
206 posix_spawn_file_actions_t actions;
207 bool actions_allocated;
208 posix_spawnattr_t attrs;
209 bool attrs_allocated;
215 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
216 block_fatal_signals ();
218 actions_allocated = false;
219 attrs_allocated = false;
220 if ((err = posix_spawn_file_actions_init (&actions)) != 0
221 || (actions_allocated = true,
223 && (err = posix_spawn_file_actions_addopen (&actions,
225 "/dev/null", O_RDONLY,
229 && (err = posix_spawn_file_actions_addopen (&actions,
235 && (err = posix_spawn_file_actions_addopen (&actions,
241 && ((err = posix_spawnattr_init (&attrs)) != 0
242 || (attrs_allocated = true,
243 (err = posix_spawnattr_setsigmask (&attrs,
246 || (err = posix_spawnattr_setflags (&attrs,
247 POSIX_SPAWN_SETSIGMASK))
249 || (err = posix_spawnp (&child, prog_path, &actions,
250 attrs_allocated ? &attrs : NULL, prog_argv,
254 if (actions_allocated)
255 posix_spawn_file_actions_destroy (&actions);
257 posix_spawnattr_destroy (&attrs);
259 unblock_fatal_signals ();
260 if (termsigp != NULL)
262 if (exit_on_error || !null_stderr)
263 error (exit_on_error ? EXIT_FAILURE : 0, err,
264 _("%s subprocess failed"), progname);
267 posix_spawn_file_actions_destroy (&actions);
269 posix_spawnattr_destroy (&attrs);
272 register_slave_subprocess (child);
273 unblock_fatal_signals ();
276 return wait_subprocess (child, progname, ignore_sigpipe, null_stderr,
277 slave_process, exit_on_error, termsigp);