1 /* Creation of subprocesses, communicating via pipes.
2 Copyright (C) 2001-2004, 2006 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 2, or (at your option)
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, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
35 #include "fatal-signal.h"
36 #include "wait-process.h"
39 #define _(str) gettext (str)
41 #if defined _MSC_VER || defined __MINGW32__
43 /* Native Woe32 API. */
45 # include "w32spawn.h"
50 # ifdef HAVE_POSIX_SPAWN
60 #ifndef HAVE_ENVIRON_DECL
61 extern char **environ;
65 # define STDIN_FILENO 0
68 # define STDOUT_FILENO 1
71 # define STDERR_FILENO 2
77 /* EINTR handling for close().
78 These functions can return -1/EINTR even though we don't have any
79 signal handlers set up, namely when we get interrupted via SIGSTOP. */
82 nonintr_close (int fd)
88 while (retval < 0 && errno == EINTR);
92 #define close nonintr_close
95 nonintr_open (const char *pathname, int oflag, mode_t mode)
100 retval = open (pathname, oflag, mode);
101 while (retval < 0 && errno == EINTR);
105 #undef open /* avoid warning on VMS */
106 #define open nonintr_open
111 /* Open a pipe connected to a child process.
114 * parent -> fd[1] -> STDIN_FILENO -> child if pipe_stdin
115 * parent <- fd[0] <- STDOUT_FILENO <- child if pipe_stdout
118 * At least one of pipe_stdin, pipe_stdout must be true.
119 * pipe_stdin and prog_stdin together determine the child's standard input.
120 * pipe_stdout and prog_stdout together determine the child's standard output.
121 * If pipe_stdin is true, prog_stdin is ignored.
122 * If pipe_stdout is true, prog_stdout is ignored.
125 create_pipe (const char *progname,
126 const char *prog_path, char **prog_argv,
127 bool pipe_stdin, bool pipe_stdout,
128 const char *prog_stdin, const char *prog_stdout,
130 bool slave_process, bool exit_on_error,
133 #if defined _MSC_VER || defined __MINGW32__
136 This uses _pipe(), dup2(), and spawnv(). It could also be implemented
137 using the low-level functions CreatePipe(), DuplicateHandle(),
138 CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
139 and cvs source code. */
150 prog_argv = prepare_spawn (prog_argv);
153 if (_pipe (ifd, 4096, O_BINARY | O_NOINHERIT) < 0)
154 error (EXIT_FAILURE, errno, _("cannot create pipe"));
156 if (_pipe (ofd, 4096, O_BINARY | O_NOINHERIT) < 0)
157 error (EXIT_FAILURE, errno, _("cannot create pipe"));
158 /* Data flow diagram:
161 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
162 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
167 /* Save standard file handles of parent process. */
168 if (pipe_stdin || prog_stdin != NULL)
169 orig_stdin = dup_noinherit (STDIN_FILENO);
170 if (pipe_stdout || prog_stdout != NULL)
171 orig_stdout = dup_noinherit (STDOUT_FILENO);
173 orig_stderr = dup_noinherit (STDERR_FILENO);
176 /* Create standard file handles of child process. */
180 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
181 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
183 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
184 && (nulloutfd == STDERR_FILENO
185 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
186 && close (nulloutfd) >= 0))))
188 || prog_stdin == NULL
189 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
190 && (stdinfd == STDIN_FILENO
191 || (dup2 (stdinfd, STDIN_FILENO) >= 0
192 && close (stdinfd) >= 0))))
194 || prog_stdout == NULL
195 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
196 && (stdoutfd == STDOUT_FILENO
197 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
198 && close (stdoutfd) >= 0)))))
199 /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
200 but it inherits all open()ed or dup2()ed file handles (which is what
201 we want in the case of STD*_FILENO) and also orig_stdin,
202 orig_stdout, orig_stderr (which is not explicitly wanted but
204 child = spawnvp (P_NOWAIT, prog_path, prog_argv);
212 /* Restore standard file handles of parent process. */
214 dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
215 if (pipe_stdout || prog_stdout != NULL)
216 dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
217 if (pipe_stdin || prog_stdin != NULL)
218 dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
226 if (exit_on_error || !null_stderr)
227 error (exit_on_error ? EXIT_FAILURE : 0, errno,
228 _("%s subprocess failed"), progname);
247 # if HAVE_POSIX_SPAWN
248 sigset_t blocked_signals;
249 posix_spawn_file_actions_t actions;
250 bool actions_allocated;
251 posix_spawnattr_t attrs;
252 bool attrs_allocated;
261 error (EXIT_FAILURE, errno, _("cannot create pipe"));
264 error (EXIT_FAILURE, errno, _("cannot create pipe"));
265 /* Data flow diagram:
268 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
269 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
274 # if HAVE_POSIX_SPAWN
277 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
278 block_fatal_signals ();
280 actions_allocated = false;
281 attrs_allocated = false;
282 if ((err = posix_spawn_file_actions_init (&actions)) != 0
283 || (actions_allocated = true,
285 && (err = posix_spawn_file_actions_adddup2 (&actions,
286 ofd[0], STDIN_FILENO))
289 && (err = posix_spawn_file_actions_adddup2 (&actions,
290 ifd[1], STDOUT_FILENO))
293 && (err = posix_spawn_file_actions_addclose (&actions, ofd[0]))
296 && (err = posix_spawn_file_actions_addclose (&actions, ifd[1]))
299 && (err = posix_spawn_file_actions_addclose (&actions, ofd[1]))
302 && (err = posix_spawn_file_actions_addclose (&actions, ifd[0]))
305 && (err = posix_spawn_file_actions_addopen (&actions,
311 && prog_stdin != NULL
312 && (err = posix_spawn_file_actions_addopen (&actions,
314 prog_stdin, O_RDONLY,
318 && prog_stdout != NULL
319 && (err = posix_spawn_file_actions_addopen (&actions,
321 prog_stdout, O_WRONLY,
325 && ((err = posix_spawnattr_init (&attrs)) != 0
326 || (attrs_allocated = true,
327 (err = posix_spawnattr_setsigmask (&attrs,
330 || (err = posix_spawnattr_setflags (&attrs,
331 POSIX_SPAWN_SETSIGMASK))
333 || (err = posix_spawnp (&child, prog_path, &actions,
334 attrs_allocated ? &attrs : NULL, prog_argv,
338 if (actions_allocated)
339 posix_spawn_file_actions_destroy (&actions);
341 posix_spawnattr_destroy (&attrs);
343 unblock_fatal_signals ();
344 if (exit_on_error || !null_stderr)
345 error (exit_on_error ? EXIT_FAILURE : 0, err,
346 _("%s subprocess failed"), progname);
359 posix_spawn_file_actions_destroy (&actions);
361 posix_spawnattr_destroy (&attrs);
364 block_fatal_signals ();
365 /* Use vfork() instead of fork() for efficiency. */
366 if ((child = vfork ()) == 0)
368 /* Child process code. */
373 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
374 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
375 && (!pipe_stdin || close (ofd[0]) >= 0)
376 && (!pipe_stdout || close (ifd[1]) >= 0)
377 && (!pipe_stdin || close (ofd[1]) >= 0)
378 && (!pipe_stdout || close (ifd[0]) >= 0)
380 || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
381 && (nulloutfd == STDERR_FILENO
382 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
383 && close (nulloutfd) >= 0))))
385 || prog_stdin == NULL
386 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
387 && (stdinfd == STDIN_FILENO
388 || (dup2 (stdinfd, STDIN_FILENO) >= 0
389 && close (stdinfd) >= 0))))
391 || prog_stdout == NULL
392 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
393 && (stdoutfd == STDOUT_FILENO
394 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
395 && close (stdoutfd) >= 0))))
396 && (!slave_process || (unblock_fatal_signals (), true)))
397 execvp (prog_path, prog_argv);
403 unblock_fatal_signals ();
404 if (exit_on_error || !null_stderr)
405 error (exit_on_error ? EXIT_FAILURE : 0, errno,
406 _("%s subprocess failed"), progname);
422 register_slave_subprocess (child);
423 unblock_fatal_signals ();
439 /* Open a bidirectional pipe.
442 * parent -> fd[1] -> STDIN_FILENO -> child
443 * parent <- fd[0] <- STDOUT_FILENO <- child
448 create_pipe_bidi (const char *progname,
449 const char *prog_path, char **prog_argv,
451 bool slave_process, bool exit_on_error,
454 pid_t result = create_pipe (progname, prog_path, prog_argv,
455 true, true, NULL, NULL,
456 null_stderr, slave_process, exit_on_error,
461 /* Open a pipe for input from a child process.
462 * The child's stdin comes from a file.
465 * parent <- fd[0] <- STDOUT_FILENO <- child
469 create_pipe_in (const char *progname,
470 const char *prog_path, char **prog_argv,
471 const char *prog_stdin, bool null_stderr,
472 bool slave_process, bool exit_on_error,
476 pid_t result = create_pipe (progname, prog_path, prog_argv,
477 false, true, prog_stdin, NULL,
478 null_stderr, slave_process, exit_on_error,
485 /* Open a pipe for output to a child process.
486 * The child's stdout goes to a file.
489 * parent -> fd[0] -> STDIN_FILENO -> child
493 create_pipe_out (const char *progname,
494 const char *prog_path, char **prog_argv,
495 const char *prog_stdout, bool null_stderr,
496 bool slave_process, bool exit_on_error,
500 pid_t result = create_pipe (progname, prog_path, prog_argv,
501 true, false, NULL, prog_stdout,
502 null_stderr, slave_process, exit_on_error,