1 /* Creation of subprocesses, communicating via pipes.
2 Copyright (C) 2001-2004, 2006-2017 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/>. */
22 #include "spawn-pipe.h"
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__) \
41 /* Native Windows API. */
43 # include "w32spawn.h"
55 /* EINTR handling for close().
56 These functions can return -1/EINTR even though we don't have any
57 signal handlers set up, namely when we get interrupted via SIGSTOP. */
60 nonintr_close (int fd
)
66 while (retval
< 0 && errno
== EINTR
);
70 #define close nonintr_close
72 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
74 nonintr_open (const char *pathname
, int oflag
, mode_t mode
)
79 retval
= open (pathname
, oflag
, mode
);
80 while (retval
< 0 && errno
== EINTR
);
84 # undef open /* avoid warning on VMS */
85 # define open nonintr_open
91 /* Open a pipe connected to a child process.
94 * parent -> fd[1] -> STDIN_FILENO -> child if pipe_stdin
95 * parent <- fd[0] <- STDOUT_FILENO <- child if pipe_stdout
98 * At least one of pipe_stdin, pipe_stdout must be true.
99 * pipe_stdin and prog_stdin together determine the child's standard input.
100 * pipe_stdout and prog_stdout together determine the child's standard output.
101 * If pipe_stdin is true, prog_stdin is ignored.
102 * If pipe_stdout is true, prog_stdout is ignored.
105 create_pipe (const char *progname
,
106 const char *prog_path
, char **prog_argv
,
107 bool pipe_stdin
, bool pipe_stdout
,
108 const char *prog_stdin
, const char *prog_stdout
,
110 bool slave_process
, bool exit_on_error
,
113 #if (((defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__) \
114 || defined __KLIBC__)
116 /* Native Windows API.
117 This uses _pipe(), dup2(), and spawnv(). It could also be implemented
118 using the low-level functions CreatePipe(), DuplicateHandle(),
119 CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
120 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 a 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
);
215 /* Restore standard file handles of parent process. */
217 undup_safer_noinherit (orig_stderr
, STDERR_FILENO
);
218 if (pipe_stdout
|| prog_stdout
!= NULL
)
219 undup_safer_noinherit (orig_stdout
, STDOUT_FILENO
);
220 if (pipe_stdin
|| prog_stdin
!= NULL
)
221 undup_safer_noinherit (orig_stdin
, STDIN_FILENO
);
229 if (exit_on_error
|| !null_stderr
)
230 error (exit_on_error
? EXIT_FAILURE
: 0, saved_errno
,
231 _("%s subprocess failed"), progname
);
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
;
260 if (pipe_safer (ifd
) < 0)
261 error (EXIT_FAILURE
, errno
, _("cannot create pipe"));
263 if (pipe_safer (ofd
) < 0)
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
276 sigprocmask (SIG_SETMASK
, NULL
, &blocked_signals
);
277 block_fatal_signals ();
279 actions_allocated
= false;
280 attrs_allocated
= false;
281 if ((err
= posix_spawn_file_actions_init (&actions
)) != 0
282 || (actions_allocated
= true,
284 && (err
= posix_spawn_file_actions_adddup2 (&actions
,
285 ofd
[0], STDIN_FILENO
))
288 && (err
= posix_spawn_file_actions_adddup2 (&actions
,
289 ifd
[1], STDOUT_FILENO
))
292 && (err
= posix_spawn_file_actions_addclose (&actions
, ofd
[0]))
295 && (err
= posix_spawn_file_actions_addclose (&actions
, ifd
[1]))
298 && (err
= posix_spawn_file_actions_addclose (&actions
, ofd
[1]))
301 && (err
= posix_spawn_file_actions_addclose (&actions
, ifd
[0]))
304 && (err
= posix_spawn_file_actions_addopen (&actions
,
310 && prog_stdin
!= NULL
311 && (err
= posix_spawn_file_actions_addopen (&actions
,
313 prog_stdin
, O_RDONLY
,
317 && prog_stdout
!= NULL
318 && (err
= posix_spawn_file_actions_addopen (&actions
,
320 prog_stdout
, O_WRONLY
,
324 && ((err
= posix_spawnattr_init (&attrs
)) != 0
325 || (attrs_allocated
= true,
326 (err
= posix_spawnattr_setsigmask (&attrs
,
329 || (err
= posix_spawnattr_setflags (&attrs
,
330 POSIX_SPAWN_SETSIGMASK
))
332 || (err
= posix_spawnp (&child
, prog_path
, &actions
,
333 attrs_allocated
? &attrs
: NULL
, prog_argv
,
337 if (actions_allocated
)
338 posix_spawn_file_actions_destroy (&actions
);
340 posix_spawnattr_destroy (&attrs
);
342 unblock_fatal_signals ();
343 if (exit_on_error
|| !null_stderr
)
344 error (exit_on_error
? EXIT_FAILURE
: 0, err
,
345 _("%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
,