1 /* Creation of subprocesses, communicating via pipes.
2 Copyright (C) 2001-2004 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. */
38 #include "fatal-signal.h"
39 #include "wait-process.h"
42 #define _(str) gettext (str)
44 #if defined _MSC_VER || defined __MINGW32__
46 /* Native Woe32 API. */
48 # include "w32spawn.h"
53 # ifdef HAVE_POSIX_SPAWN
63 #ifndef HAVE_ENVIRON_DECL
64 extern char **environ;
68 # define STDIN_FILENO 0
71 # define STDOUT_FILENO 1
74 # define STDERR_FILENO 2
80 /* EINTR handling for close().
81 These functions can return -1/EINTR even though we don't have any
82 signal handlers set up, namely when we get interrupted via SIGSTOP. */
85 nonintr_close (int fd)
91 while (retval < 0 && errno == EINTR);
95 #define close nonintr_close
98 nonintr_open (const char *pathname, int oflag, mode_t mode)
103 retval = open (pathname, oflag, mode);
104 while (retval < 0 && errno == EINTR);
108 #undef open /* avoid warning on VMS */
109 #define open nonintr_open
114 /* Open a pipe connected to a child process.
117 * parent -> fd[1] -> STDIN_FILENO -> child if pipe_stdin
118 * parent <- fd[0] <- STDOUT_FILENO <- child if pipe_stdout
121 * At least one of pipe_stdin, pipe_stdout must be true.
122 * pipe_stdin and prog_stdin together determine the child's standard input.
123 * pipe_stdout and prog_stdout together determine the child's standard output.
124 * If pipe_stdin is true, prog_stdin is ignored.
125 * If pipe_stdout is true, prog_stdout is ignored.
128 create_pipe (const char *progname,
129 const char *prog_path, char **prog_argv,
130 bool pipe_stdin, bool pipe_stdout,
131 const char *prog_stdin, const char *prog_stdout,
133 bool slave_process, bool exit_on_error,
136 #if defined _MSC_VER || defined __MINGW32__
139 This uses _pipe(), dup2(), and spawnv(). It could also be implemented
140 using the low-level functions CreatePipe(), DuplicateHandle(),
141 CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
142 and cvs source code. */
153 prog_argv = prepare_spawn (prog_argv);
156 if (_pipe (ifd, 4096, O_BINARY | O_NOINHERIT) < 0)
157 error (EXIT_FAILURE, errno, _("cannot create pipe"));
159 if (_pipe (ofd, 4096, O_BINARY | O_NOINHERIT) < 0)
160 error (EXIT_FAILURE, errno, _("cannot create pipe"));
161 /* Data flow diagram:
164 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
165 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
170 /* Save standard file handles of parent process. */
171 if (pipe_stdin || prog_stdin != NULL)
172 orig_stdin = dup_noinherit (STDIN_FILENO);
173 if (pipe_stdout || prog_stdout != NULL)
174 orig_stdout = dup_noinherit (STDOUT_FILENO);
176 orig_stderr = dup_noinherit (STDERR_FILENO);
179 /* Create standard file handles of child process. */
183 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
184 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
186 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
187 && (nulloutfd == STDERR_FILENO
188 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
189 && close (nulloutfd) >= 0))))
191 || prog_stdin == NULL
192 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
193 && (stdinfd == STDIN_FILENO
194 || (dup2 (stdinfd, STDIN_FILENO) >= 0
195 && close (stdinfd) >= 0))))
197 || prog_stdout == NULL
198 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
199 && (stdoutfd == STDOUT_FILENO
200 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
201 && close (stdoutfd) >= 0)))))
202 /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
203 but it inherits all open()ed or dup2()ed file handles (which is what
204 we want in the case of STD*_FILENO) and also orig_stdin,
205 orig_stdout, orig_stderr (which is not explicitly wanted but
207 child = spawnvp (P_NOWAIT, prog_path, prog_argv);
215 /* Restore standard file handles of parent process. */
217 dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
218 if (pipe_stdout || prog_stdout != NULL)
219 dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
220 if (pipe_stdin || prog_stdin != NULL)
221 dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
229 if (exit_on_error || !null_stderr)
230 error (exit_on_error ? EXIT_FAILURE : 0, errno,
231 _("%s subprocess failed"), progname);
250 # if HAVE_POSIX_SPAWN
251 sigset_t blocked_signals;
252 posix_spawn_file_actions_t actions;
253 bool actions_allocated;
254 posix_spawnattr_t attrs;
255 bool attrs_allocated;
264 error (EXIT_FAILURE, errno, _("cannot create pipe"));
267 error (EXIT_FAILURE, errno, _("cannot create pipe"));
268 /* Data flow diagram:
271 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
272 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
277 # if HAVE_POSIX_SPAWN
280 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
281 block_fatal_signals ();
283 actions_allocated = false;
284 attrs_allocated = false;
285 if ((err = posix_spawn_file_actions_init (&actions)) != 0
286 || (actions_allocated = true,
288 && (err = posix_spawn_file_actions_adddup2 (&actions,
289 ofd[0], STDIN_FILENO))
292 && (err = posix_spawn_file_actions_adddup2 (&actions,
293 ifd[1], STDOUT_FILENO))
296 && (err = posix_spawn_file_actions_addclose (&actions, ofd[0]))
299 && (err = posix_spawn_file_actions_addclose (&actions, ifd[1]))
302 && (err = posix_spawn_file_actions_addclose (&actions, ofd[1]))
305 && (err = posix_spawn_file_actions_addclose (&actions, ifd[0]))
308 && (err = posix_spawn_file_actions_addopen (&actions,
314 && prog_stdin != NULL
315 && (err = posix_spawn_file_actions_addopen (&actions,
317 prog_stdin, O_RDONLY,
321 && prog_stdout != NULL
322 && (err = posix_spawn_file_actions_addopen (&actions,
324 prog_stdout, O_WRONLY,
328 && ((err = posix_spawnattr_init (&attrs)) != 0
329 || (attrs_allocated = true,
330 (err = posix_spawnattr_setsigmask (&attrs,
333 || (err = posix_spawnattr_setflags (&attrs,
334 POSIX_SPAWN_SETSIGMASK))
336 || (err = posix_spawnp (&child, prog_path, &actions,
337 attrs_allocated ? &attrs : NULL, prog_argv,
341 if (actions_allocated)
342 posix_spawn_file_actions_destroy (&actions);
344 posix_spawnattr_destroy (&attrs);
346 unblock_fatal_signals ();
347 if (exit_on_error || !null_stderr)
348 error (exit_on_error ? EXIT_FAILURE : 0, err,
349 _("%s subprocess failed"), progname);
362 posix_spawn_file_actions_destroy (&actions);
364 posix_spawnattr_destroy (&attrs);
367 block_fatal_signals ();
368 /* Use vfork() instead of fork() for efficiency. */
369 if ((child = vfork ()) == 0)
371 /* Child process code. */
376 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
377 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
378 && (!pipe_stdin || close (ofd[0]) >= 0)
379 && (!pipe_stdout || close (ifd[1]) >= 0)
380 && (!pipe_stdin || close (ofd[1]) >= 0)
381 && (!pipe_stdout || close (ifd[0]) >= 0)
383 || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
384 && (nulloutfd == STDERR_FILENO
385 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
386 && close (nulloutfd) >= 0))))
388 || prog_stdin == NULL
389 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
390 && (stdinfd == STDIN_FILENO
391 || (dup2 (stdinfd, STDIN_FILENO) >= 0
392 && close (stdinfd) >= 0))))
394 || prog_stdout == NULL
395 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
396 && (stdoutfd == STDOUT_FILENO
397 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
398 && close (stdoutfd) >= 0))))
399 && (!slave_process || (unblock_fatal_signals (), true)))
400 execvp (prog_path, prog_argv);
406 unblock_fatal_signals ();
407 if (exit_on_error || !null_stderr)
408 error (exit_on_error ? EXIT_FAILURE : 0, errno,
409 _("%s subprocess failed"), progname);
425 register_slave_subprocess (child);
426 unblock_fatal_signals ();
442 /* Open a bidirectional pipe.
445 * parent -> fd[1] -> STDIN_FILENO -> child
446 * parent <- fd[0] <- STDOUT_FILENO <- child
451 create_pipe_bidi (const char *progname,
452 const char *prog_path, char **prog_argv,
454 bool slave_process, bool exit_on_error,
457 pid_t result = create_pipe (progname, prog_path, prog_argv,
458 true, true, NULL, NULL,
459 null_stderr, slave_process, exit_on_error,
464 /* Open a pipe for input from a child process.
465 * The child's stdin comes from a file.
468 * parent <- fd[0] <- STDOUT_FILENO <- child
472 create_pipe_in (const char *progname,
473 const char *prog_path, char **prog_argv,
474 const char *prog_stdin, bool null_stderr,
475 bool slave_process, bool exit_on_error,
479 pid_t result = create_pipe (progname, prog_path, prog_argv,
480 false, true, prog_stdin, NULL,
481 null_stderr, slave_process, exit_on_error,
488 /* Open a pipe for output to a child process.
489 * The child's stdout goes to a file.
492 * parent -> fd[0] -> STDIN_FILENO -> child
496 create_pipe_out (const char *progname,
497 const char *prog_path, char **prog_argv,
498 const char *prog_stdout, bool null_stderr,
499 bool slave_process, bool exit_on_error,
503 pid_t result = create_pipe (progname, prog_path, prog_argv,
504 true, false, NULL, prog_stdout,
505 null_stderr, slave_process, exit_on_error,