1 /* Creation of subprocesses, communicating via pipes.
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/>. */
31 #include "fatal-signal.h"
32 #include "unistd-safer.h"
33 #include "wait-process.h"
36 #define _(str) gettext (str)
38 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
40 /* Native Woe32 API. */
42 # include "w32spawn.h"
51 /* The results of open() in this file are not used with fchdir,
52 therefore save some unnecessary work in fchdir.c. */
59 /* EINTR handling for close().
60 These functions can return -1/EINTR even though we don't have any
61 signal handlers set up, namely when we get interrupted via SIGSTOP. */
64 nonintr_close (int fd)
70 while (retval < 0 && errno == EINTR);
74 #define close nonintr_close
77 nonintr_open (const char *pathname, int oflag, mode_t mode)
82 retval = open (pathname, oflag, mode);
83 while (retval < 0 && errno == EINTR);
87 #undef open /* avoid warning on VMS */
88 #define open nonintr_open
93 /* Open a pipe connected to a child process.
96 * parent -> fd[1] -> STDIN_FILENO -> child if pipe_stdin
97 * parent <- fd[0] <- STDOUT_FILENO <- child if pipe_stdout
100 * At least one of pipe_stdin, pipe_stdout must be true.
101 * pipe_stdin and prog_stdin together determine the child's standard input.
102 * pipe_stdout and prog_stdout together determine the child's standard output.
103 * If pipe_stdin is true, prog_stdin is ignored.
104 * If pipe_stdout is true, prog_stdout is ignored.
107 create_pipe (const char *progname,
108 const char *prog_path, char **prog_argv,
109 bool pipe_stdin, bool pipe_stdout,
110 const char *prog_stdin, const char *prog_stdout,
112 bool slave_process, bool exit_on_error,
115 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
118 This uses _pipe(), dup2(), and spawnv(). It could also be implemented
119 using the low-level functions CreatePipe(), DuplicateHandle(),
120 CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
121 and cvs source code. */
132 /* FIXME: Need to free memory allocated by prepare_spawn. */
133 prog_argv = prepare_spawn (prog_argv);
136 if (pipe2_safer (ifd, O_BINARY | O_CLOEXEC) < 0)
137 error (EXIT_FAILURE, errno, _("cannot create pipe"));
139 if (pipe2_safer (ofd, O_BINARY | O_CLOEXEC) < 0)
140 error (EXIT_FAILURE, errno, _("cannot create pipe"));
141 /* Data flow diagram:
144 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
145 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
150 /* Save standard file handles of parent process. */
151 if (pipe_stdin || prog_stdin != NULL)
152 orig_stdin = dup_safer_noinherit (STDIN_FILENO);
153 if (pipe_stdout || prog_stdout != NULL)
154 orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
156 orig_stderr = dup_safer_noinherit (STDERR_FILENO);
159 /* Create standard file handles of child process. */
163 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
164 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
166 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
167 && (nulloutfd == STDERR_FILENO
168 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
169 && close (nulloutfd) >= 0))))
171 || prog_stdin == NULL
172 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
173 && (stdinfd == STDIN_FILENO
174 || (dup2 (stdinfd, STDIN_FILENO) >= 0
175 && close (stdinfd) >= 0))))
177 || prog_stdout == NULL
178 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
179 && (stdoutfd == STDOUT_FILENO
180 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
181 && close (stdoutfd) >= 0)))))
182 /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
183 but it inherits all open()ed or dup2()ed file handles (which is what
184 we want in the case of STD*_FILENO). */
185 /* Use spawnvpe and pass the environment explicitly. This is needed if
186 the program has modified the environment using putenv() or [un]setenv().
187 On Windows, programs have two environments, one in the "environment
188 block" of the process and managed through SetEnvironmentVariable(), and
189 one inside the process, in the location retrieved by the 'environ'
190 macro. When using spawnvp() without 'e', the child process inherits a
191 copy of the environment block - ignoring the effects of putenv() and
194 child = spawnvpe (P_NOWAIT, prog_path, (const char **) prog_argv,
195 (const char **) environ);
196 if (child < 0 && errno == ENOEXEC)
198 /* prog is not an native executable. Try to execute it as a
199 shell script. Note that prepare_spawn() has already prepended
200 a hidden element "sh.exe" to prog_argv. */
202 child = spawnvpe (P_NOWAIT, prog_argv[0], (const char **) prog_argv,
203 (const char **) environ);
213 /* Restore standard file handles of parent process. */
215 undup_safer_noinherit (orig_stderr, STDERR_FILENO);
216 if (pipe_stdout || prog_stdout != NULL)
217 undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
218 if (pipe_stdin || prog_stdin != NULL)
219 undup_safer_noinherit (orig_stdin, STDIN_FILENO);
227 if (exit_on_error || !null_stderr)
228 error (exit_on_error ? EXIT_FAILURE : 0, errno,
229 _("%s subprocess failed"), progname);
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;
257 if (pipe_safer (ifd) < 0)
258 error (EXIT_FAILURE, errno, _("cannot create pipe"));
260 if (pipe_safer (ofd) < 0)
261 error (EXIT_FAILURE, errno, _("cannot create pipe"));
262 /* Data flow diagram:
265 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
266 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
273 sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
274 block_fatal_signals ();
276 actions_allocated = false;
277 attrs_allocated = false;
278 if ((err = posix_spawn_file_actions_init (&actions)) != 0
279 || (actions_allocated = true,
281 && (err = posix_spawn_file_actions_adddup2 (&actions,
282 ofd[0], STDIN_FILENO))
285 && (err = posix_spawn_file_actions_adddup2 (&actions,
286 ifd[1], STDOUT_FILENO))
289 && (err = posix_spawn_file_actions_addclose (&actions, ofd[0]))
292 && (err = posix_spawn_file_actions_addclose (&actions, ifd[1]))
295 && (err = posix_spawn_file_actions_addclose (&actions, ofd[1]))
298 && (err = posix_spawn_file_actions_addclose (&actions, ifd[0]))
301 && (err = posix_spawn_file_actions_addopen (&actions,
307 && prog_stdin != NULL
308 && (err = posix_spawn_file_actions_addopen (&actions,
310 prog_stdin, O_RDONLY,
314 && prog_stdout != NULL
315 && (err = posix_spawn_file_actions_addopen (&actions,
317 prog_stdout, O_WRONLY,
321 && ((err = posix_spawnattr_init (&attrs)) != 0
322 || (attrs_allocated = true,
323 (err = posix_spawnattr_setsigmask (&attrs,
326 || (err = posix_spawnattr_setflags (&attrs,
327 POSIX_SPAWN_SETSIGMASK))
329 || (err = posix_spawnp (&child, prog_path, &actions,
330 attrs_allocated ? &attrs : NULL, prog_argv,
334 if (actions_allocated)
335 posix_spawn_file_actions_destroy (&actions);
337 posix_spawnattr_destroy (&attrs);
339 unblock_fatal_signals ();
340 if (exit_on_error || !null_stderr)
341 error (exit_on_error ? EXIT_FAILURE : 0, err,
342 _("%s subprocess failed"), progname);
355 posix_spawn_file_actions_destroy (&actions);
357 posix_spawnattr_destroy (&attrs);
360 register_slave_subprocess (child);
361 unblock_fatal_signals ();
377 /* Open a bidirectional pipe.
380 * parent -> fd[1] -> STDIN_FILENO -> child
381 * parent <- fd[0] <- STDOUT_FILENO <- child
386 create_pipe_bidi (const char *progname,
387 const char *prog_path, char **prog_argv,
389 bool slave_process, bool exit_on_error,
392 pid_t result = create_pipe (progname, prog_path, prog_argv,
393 true, true, NULL, NULL,
394 null_stderr, slave_process, exit_on_error,
399 /* Open a pipe for input from a child process.
400 * The child's stdin comes from a file.
403 * parent <- fd[0] <- STDOUT_FILENO <- child
407 create_pipe_in (const char *progname,
408 const char *prog_path, char **prog_argv,
409 const char *prog_stdin, bool null_stderr,
410 bool slave_process, bool exit_on_error,
414 pid_t result = create_pipe (progname, prog_path, prog_argv,
415 false, true, prog_stdin, NULL,
416 null_stderr, slave_process, exit_on_error,
423 /* Open a pipe for output to a child process.
424 * The child's stdout goes to a file.
427 * parent -> fd[0] -> STDIN_FILENO -> child
431 create_pipe_out (const char *progname,
432 const char *prog_path, char **prog_argv,
433 const char *prog_stdout, bool null_stderr,
434 bool slave_process, bool exit_on_error,
438 pid_t result = create_pipe (progname, prog_path, prog_argv,
439 true, false, NULL, prog_stdout,
440 null_stderr, slave_process, exit_on_error,