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 (ifd, O_BINARY | O_NOINHERIT) < 0
137 || (ifd[0] = fd_safer_noinherit (ifd[0])) < 0
138 || (ifd[1] = fd_safer_noinherit (ifd[1])) < 0)
139 error (EXIT_FAILURE, errno, _("cannot create pipe"));
141 if (pipe2 (ofd, O_BINARY | O_NOINHERIT) < 0
142 || (ofd[0] = fd_safer_noinherit (ofd[0])) < 0
143 || (ofd[1] = fd_safer_noinherit (ofd[1])) < 0)
144 error (EXIT_FAILURE, errno, _("cannot create pipe"));
145 /* Data flow diagram:
148 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
149 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
154 /* Save standard file handles of parent process. */
155 if (pipe_stdin || prog_stdin != NULL)
156 orig_stdin = dup_safer_noinherit (STDIN_FILENO);
157 if (pipe_stdout || prog_stdout != NULL)
158 orig_stdout = dup_safer_noinherit (STDOUT_FILENO);
160 orig_stderr = dup_safer_noinherit (STDERR_FILENO);
163 /* Create standard file handles of child process. */
167 if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
168 && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
170 || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
171 && (nulloutfd == STDERR_FILENO
172 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
173 && close (nulloutfd) >= 0))))
175 || prog_stdin == NULL
176 || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
177 && (stdinfd == STDIN_FILENO
178 || (dup2 (stdinfd, STDIN_FILENO) >= 0
179 && close (stdinfd) >= 0))))
181 || prog_stdout == NULL
182 || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
183 && (stdoutfd == STDOUT_FILENO
184 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
185 && close (stdoutfd) >= 0)))))
186 /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
187 but it inherits all open()ed or dup2()ed file handles (which is what
188 we want in the case of STD*_FILENO). */
189 /* Use spawnvpe and pass the environment explicitly. This is needed if
190 the program has modified the environment using putenv() or [un]setenv().
191 On Windows, programs have two environments, one in the "environment
192 block" of the process and managed through SetEnvironmentVariable(), and
193 one inside the process, in the location retrieved by the 'environ'
194 macro. When using spawnvp() without 'e', the child process inherits a
195 copy of the environment block - ignoring the effects of putenv() and
198 child = spawnvpe (P_NOWAIT, prog_path, (const char **) prog_argv,
199 (const char **) environ);
200 if (child < 0 && errno == ENOEXEC)
202 /* prog is not an native executable. Try to execute it as a
203 shell script. Note that prepare_spawn() has already prepended
204 a hidden element "sh.exe" to prog_argv. */
206 child = spawnvpe (P_NOWAIT, prog_argv[0], (const char **) prog_argv,
207 (const char **) environ);
217 /* Restore standard file handles of parent process. */
219 undup_safer_noinherit (orig_stderr, STDERR_FILENO);
220 if (pipe_stdout || prog_stdout != NULL)
221 undup_safer_noinherit (orig_stdout, STDOUT_FILENO);
222 if (pipe_stdin || prog_stdin != NULL)
223 undup_safer_noinherit (orig_stdin, STDIN_FILENO);
231 if (exit_on_error || !null_stderr)
232 error (exit_on_error ? EXIT_FAILURE : 0, errno,
233 _("%s subprocess failed"), progname);
252 sigset_t blocked_signals;
253 posix_spawn_file_actions_t actions;
254 bool actions_allocated;
255 posix_spawnattr_t attrs;
256 bool attrs_allocated;
261 if (pipe_safer (ifd) < 0)
262 error (EXIT_FAILURE, errno, _("cannot create pipe"));
264 if (pipe_safer (ofd) < 0)
265 error (EXIT_FAILURE, errno, _("cannot create pipe"));
266 /* Data flow diagram:
269 * parent -> ofd[1] -> ofd[0] -> child if pipe_stdin
270 * parent <- ifd[0] <- ifd[1] <- child if pipe_stdout
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 register_slave_subprocess (child);
365 unblock_fatal_signals ();
381 /* Open a bidirectional pipe.
384 * parent -> fd[1] -> STDIN_FILENO -> child
385 * parent <- fd[0] <- STDOUT_FILENO <- child
390 create_pipe_bidi (const char *progname,
391 const char *prog_path, char **prog_argv,
393 bool slave_process, bool exit_on_error,
396 pid_t result = create_pipe (progname, prog_path, prog_argv,
397 true, true, NULL, NULL,
398 null_stderr, slave_process, exit_on_error,
403 /* Open a pipe for input from a child process.
404 * The child's stdin comes from a file.
407 * parent <- fd[0] <- STDOUT_FILENO <- child
411 create_pipe_in (const char *progname,
412 const char *prog_path, char **prog_argv,
413 const char *prog_stdin, bool null_stderr,
414 bool slave_process, bool exit_on_error,
418 pid_t result = create_pipe (progname, prog_path, prog_argv,
419 false, true, prog_stdin, NULL,
420 null_stderr, slave_process, exit_on_error,
427 /* Open a pipe for output to a child process.
428 * The child's stdout goes to a file.
431 * parent -> fd[0] -> STDIN_FILENO -> child
435 create_pipe_out (const char *progname,
436 const char *prog_path, char **prog_argv,
437 const char *prog_stdout, bool null_stderr,
438 bool slave_process, bool exit_on_error,
442 pid_t result = create_pipe (progname, prog_path, prog_argv,
443 true, false, NULL, prog_stdout,
444 null_stderr, slave_process, exit_on_error,