1 /* gspawn.c - Process launching
3 * Copyright 2000 Red Hat, Inc.
4 * g_execvpe implementation based on GNU libc execvp:
5 * Copyright 1991, 92, 95, 96, 97, 98, 99 Free Software Foundation, Inc.
7 * GLib is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public License as
9 * published by the Free Software Foundation; either version 2 of the
10 * License, or (at your option) any later version.
12 * GLib is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with GLib; see the file COPYING.LIB. If not, write
19 * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20 * Boston, MA 02111-1307, USA.
26 #include <sys/types.h>
33 #include <stdlib.h> /* for fdwalk */
36 #ifdef HAVE_SYS_SELECT_H
37 #include <sys/select.h>
38 #endif /* HAVE_SYS_SELECT_H */
40 #ifdef HAVE_SYS_RESOURCE_H
41 #include <sys/resource.h>
42 #endif /* HAVE_SYS_RESOURCE_H */
49 #include "gstrfuncs.h"
50 #include "gtestutils.h"
54 static gint g_execute (const gchar *file,
57 gboolean search_path);
59 static gboolean make_pipe (gint p[2],
61 static gboolean fork_exec_with_pipes (gboolean intermediate_child,
62 const gchar *working_directory,
65 gboolean close_descriptors,
67 gboolean stdout_to_null,
68 gboolean stderr_to_null,
69 gboolean child_inherits_stdin,
70 gboolean file_and_argv_zero,
71 GSpawnChildSetupFunc child_setup,
75 gint *standard_output,
80 g_spawn_error_quark (void)
82 return g_quark_from_static_string ("g-exec-error-quark");
87 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
88 * @argv: (array zero-terminated=1): child's argument vector
89 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
90 * @flags: flags from #GSpawnFlags
91 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
92 * @user_data: (closure): user data for @child_setup
93 * @child_pid: (out) (allow-none): return location for child process reference, or %NULL
94 * @error: return location for error
96 * See g_spawn_async_with_pipes() for a full description; this function
97 * simply calls the g_spawn_async_with_pipes() without any pipes.
99 * You should call g_spawn_close_pid() on the returned child process
100 * reference when you don't need it any more.
103 * If you are writing a GTK+ application, and the program you
104 * are spawning is a graphical application, too, then you may
105 * want to use gdk_spawn_on_screen() instead to ensure that
106 * the spawned program opens its windows on the right screen.
109 * <note><para> Note that the returned @child_pid on Windows is a
110 * handle to the child process and not its identifier. Process handles
111 * and process identifiers are different concepts on Windows.
114 * Return value: %TRUE on success, %FALSE if error is set
117 g_spawn_async (const gchar *working_directory,
121 GSpawnChildSetupFunc child_setup,
126 g_return_val_if_fail (argv != NULL, FALSE);
128 return g_spawn_async_with_pipes (working_directory,
138 /* Avoids a danger in threaded situations (calling close()
139 * on a file descriptor twice, and another thread has
140 * re-opened it since the first close)
143 close_and_invalidate (gint *fd)
153 if (ret == -1 && errno == EINTR)
161 /* Some versions of OS X define READ_OK in public headers */
166 READ_FAILED = 0, /* FALSE */
172 read_data (GString *str,
180 bytes = read (fd, buf, 4096);
186 g_string_append_len (str, buf, bytes);
189 else if (errno == EINTR)
198 _("Failed to read data from child process (%s)"),
207 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
208 * @argv: (array zero-terminated=1): child's argument vector
209 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
210 * @flags: flags from #GSpawnFlags
211 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
212 * @user_data: (closure): user data for @child_setup
213 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output, or %NULL
214 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child error messages, or %NULL
215 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid(), or %NULL
216 * @error: return location for error, or %NULL
218 * Executes a child synchronously (waits for the child to exit before returning).
219 * All output from the child is stored in @standard_output and @standard_error,
220 * if those parameters are non-%NULL. Note that you must set the
221 * %G_SPAWN_STDOUT_TO_DEV_NULL and %G_SPAWN_STDERR_TO_DEV_NULL flags when
222 * passing %NULL for @standard_output and @standard_error.
223 * If @exit_status is non-%NULL, the exit status of the child is stored
224 * there as it would be returned by waitpid(); standard UNIX macros such
225 * as WIFEXITED() and WEXITSTATUS() must be used to evaluate the exit status.
226 * Note that this function call waitpid() even if @exit_status is %NULL, and
227 * does not accept the %G_SPAWN_DO_NOT_REAP_CHILD flag.
228 * If an error occurs, no data is returned in @standard_output,
229 * @standard_error, or @exit_status.
231 * This function calls g_spawn_async_with_pipes() internally; see that
232 * function for full details on the other parameters and details on
233 * how these functions work on Windows.
235 * Return value: %TRUE on success, %FALSE if an error was set.
238 g_spawn_sync (const gchar *working_directory,
242 GSpawnChildSetupFunc child_setup,
244 gchar **standard_output,
245 gchar **standard_error,
254 GString *outstr = NULL;
255 GString *errstr = NULL;
259 g_return_val_if_fail (argv != NULL, FALSE);
260 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
261 g_return_val_if_fail (standard_output == NULL ||
262 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
263 g_return_val_if_fail (standard_error == NULL ||
264 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
266 /* Just to ensure segfaults if callers try to use
267 * these when an error is reported.
270 *standard_output = NULL;
273 *standard_error = NULL;
275 if (!fork_exec_with_pipes (FALSE,
279 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
280 (flags & G_SPAWN_SEARCH_PATH) != 0,
281 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
282 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
283 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
284 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
289 standard_output ? &outpipe : NULL,
290 standard_error ? &errpipe : NULL,
294 /* Read data from child. */
300 outstr = g_string_new (NULL);
305 errstr = g_string_new (NULL);
308 /* Read data until we get EOF on both pipes. */
317 FD_SET (outpipe, &fds);
319 FD_SET (errpipe, &fds);
321 ret = select (MAX (outpipe, errpipe) + 1,
324 NULL /* no timeout */);
338 _("Unexpected error in select() reading data from a child process (%s)"),
344 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
346 switch (read_data (outstr, outpipe, error))
352 close_and_invalidate (&outpipe);
363 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
365 switch (read_data (errstr, errpipe, error))
371 close_and_invalidate (&errpipe);
383 /* These should only be open still if we had an error. */
386 close_and_invalidate (&outpipe);
388 close_and_invalidate (&errpipe);
390 /* Wait for child to exit, even if we have
395 ret = waitpid (pid, &status, 0);
401 else if (errno == ECHILD)
405 g_warning ("In call to g_spawn_sync(), exit status of a child process was requested but SIGCHLD action was set to SIG_IGN and ECHILD was received by waitpid(), so exit status can't be returned. This is a bug in the program calling g_spawn_sync(); either don't request the exit status, or don't set the SIGCHLD action.");
409 /* We don't need the exit status. */
414 if (!failed) /* avoid error pileups */
423 _("Unexpected error in waitpid() (%s)"),
432 g_string_free (outstr, TRUE);
434 g_string_free (errstr, TRUE);
441 *exit_status = status;
444 *standard_output = g_string_free (outstr, FALSE);
447 *standard_error = g_string_free (errstr, FALSE);
454 * g_spawn_async_with_pipes:
455 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
456 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
457 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
458 * @flags: flags from #GSpawnFlags
459 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
460 * @user_data: (closure): user data for @child_setup
461 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
462 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
463 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
464 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
465 * @error: return location for error
467 * Executes a child program asynchronously (your program will not
468 * block waiting for the child to exit). The child program is
469 * specified by the only argument that must be provided, @argv. @argv
470 * should be a %NULL-terminated array of strings, to be passed as the
471 * argument vector for the child. The first string in @argv is of
472 * course the name of the program to execute. By default, the name of
473 * the program must be a full path; the <envar>PATH</envar> shell variable
474 * will only be searched if you pass the %G_SPAWN_SEARCH_PATH flag.
476 * On Windows, note that all the string or string vector arguments to
477 * this function and the other g_spawn*() functions are in UTF-8, the
478 * GLib file name encoding. Unicode characters that are not part of
479 * the system codepage passed in these arguments will be correctly
480 * available in the spawned program only if it uses wide character API
481 * to retrieve its command line. For C programs built with Microsoft's
482 * tools it is enough to make the program have a wmain() instead of
483 * main(). wmain() has a wide character argument vector as parameter.
485 * At least currently, mingw doesn't support wmain(), so if you use
486 * mingw to develop the spawned program, it will have to call the
487 * undocumented function __wgetmainargs() to get the wide character
488 * argument vector and environment. See gspawn-win32-helper.c in the
489 * GLib sources or init.c in the mingw runtime sources for a prototype
490 * for that function. Alternatively, you can retrieve the Win32 system
491 * level wide character command line passed to the spawned program
492 * using the GetCommandLineW() function.
494 * On Windows the low-level child process creation API
495 * <function>CreateProcess()</function> doesn't use argument vectors,
496 * but a command line. The C runtime library's
497 * <function>spawn*()</function> family of functions (which
498 * g_spawn_async_with_pipes() eventually calls) paste the argument
499 * vector elements together into a command line, and the C runtime startup code
500 * does a corresponding reconstruction of an argument vector from the
501 * command line, to be passed to main(). Complications arise when you have
502 * argument vector elements that contain spaces of double quotes. The
503 * <function>spawn*()</function> functions don't do any quoting or
504 * escaping, but on the other hand the startup code does do unquoting
505 * and unescaping in order to enable receiving arguments with embedded
506 * spaces or double quotes. To work around this asymmetry,
507 * g_spawn_async_with_pipes() will do quoting and escaping on argument
508 * vector elements that need it before calling the C runtime
511 * The returned @child_pid on Windows is a handle to the child
512 * process, not its identifier. Process handles and process
513 * identifiers are different concepts on Windows.
515 * @envp is a %NULL-terminated array of strings, where each string
516 * has the form <literal>KEY=VALUE</literal>. This will become
517 * the child's environment. If @envp is %NULL, the child inherits its
518 * parent's environment.
520 * @flags should be the bitwise OR of any flags you want to affect the
521 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that
522 * the child will not automatically be reaped; you must use a
523 * #GChildWatch source to be notified about the death of the child
524 * process. Eventually you must call g_spawn_close_pid() on the
525 * @child_pid, in order to free resources which may be associated
526 * with the child process. (On Unix, using a #GChildWatch source is
527 * equivalent to calling waitpid() or handling the %SIGCHLD signal
528 * manually. On Windows, calling g_spawn_close_pid() is equivalent
529 * to calling CloseHandle() on the process handle returned in
532 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
533 * descriptors will be inherited by the child; otherwise all
534 * descriptors except stdin/stdout/stderr will be closed before
535 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
536 * means that <literal>argv[0]</literal> need not be an absolute path, it
537 * will be looked for in the user's <envar>PATH</envar>.
538 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
539 * be discarded, instead of going to the same location as the parent's
540 * standard output. If you use this flag, @standard_output must be %NULL.
541 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
542 * will be discarded, instead of going to the same location as the parent's
543 * standard error. If you use this flag, @standard_error must be %NULL.
544 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
545 * standard input (by default, the child's standard input is attached to
546 * /dev/null). If you use this flag, @standard_input must be %NULL.
547 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
548 * the file to execute, while the remaining elements are the
549 * actual argument vector to pass to the file. Normally
550 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
551 * passes all of @argv to the child.
553 * @child_setup and @user_data are a function and user data. On POSIX
554 * platforms, the function is called in the child after GLib has
555 * performed all the setup it plans to perform (including creating
556 * pipes, closing file descriptors, etc.) but before calling
557 * exec(). That is, @child_setup is called just
558 * before calling exec() in the child. Obviously
559 * actions taken in this function will only affect the child, not the
562 * On Windows, there is no separate fork() and exec()
563 * functionality. Child processes are created and run with a single
564 * API call, CreateProcess(). There is no sensible thing @child_setup
565 * could be used for on Windows so it is ignored and not called.
567 * If non-%NULL, @child_pid will on Unix be filled with the child's
568 * process ID. You can use the process ID to send signals to the
569 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
570 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
571 * filled with a handle to the child process only if you specified the
572 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
573 * process using the Win32 API, for example wait for its termination
574 * with the <function>WaitFor*()</function> functions, or examine its
575 * exit code with GetExitCodeProcess(). You should close the handle
576 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
578 * If non-%NULL, the @standard_input, @standard_output, @standard_error
579 * locations will be filled with file descriptors for writing to the child's
580 * standard input or reading from its standard output or standard error.
581 * The caller of g_spawn_async_with_pipes() must close these file descriptors
582 * when they are no longer in use. If these parameters are %NULL, the corresponding
583 * pipe won't be created.
585 * If @standard_input is NULL, the child's standard input is attached to
586 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
588 * If @standard_error is NULL, the child's standard error goes to the same
589 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
592 * If @standard_output is NULL, the child's standard output goes to the same
593 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
596 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
597 * If an error is set, the function returns %FALSE. Errors
598 * are reported even if they occur in the child (for example if the
599 * executable in <literal>argv[0]</literal> is not found). Typically
600 * the <literal>message</literal> field of returned errors should be displayed
601 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
603 * If an error occurs, @child_pid, @standard_input, @standard_output,
604 * and @standard_error will not be filled with valid values.
606 * If @child_pid is not %NULL and an error does not occur then the returned
607 * process reference must be closed using g_spawn_close_pid().
610 * If you are writing a GTK+ application, and the program you
611 * are spawning is a graphical application, too, then you may
612 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
613 * the spawned program opens its windows on the right screen.
616 * Return value: %TRUE on success, %FALSE if an error was set
619 g_spawn_async_with_pipes (const gchar *working_directory,
623 GSpawnChildSetupFunc child_setup,
626 gint *standard_input,
627 gint *standard_output,
628 gint *standard_error,
631 g_return_val_if_fail (argv != NULL, FALSE);
632 g_return_val_if_fail (standard_output == NULL ||
633 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
634 g_return_val_if_fail (standard_error == NULL ||
635 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
636 /* can't inherit stdin if we have an input pipe. */
637 g_return_val_if_fail (standard_input == NULL ||
638 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
640 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
644 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
645 (flags & G_SPAWN_SEARCH_PATH) != 0,
646 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
647 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
648 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
649 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
660 * g_spawn_command_line_sync:
661 * @command_line: a command line
662 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
663 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
664 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
665 * @error: return location for errors
667 * A simple version of g_spawn_sync() with little-used parameters
668 * removed, taking a command line instead of an argument vector. See
669 * g_spawn_sync() for full details. @command_line will be parsed by
670 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
671 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
672 * implications, so consider using g_spawn_sync() directly if
673 * appropriate. Possible errors are those from g_spawn_sync() and those
674 * from g_shell_parse_argv().
676 * If @exit_status is non-%NULL, the exit status of the child is stored there as
677 * it would be returned by waitpid(); standard UNIX macros such as WIFEXITED()
678 * and WEXITSTATUS() must be used to evaluate the exit status.
680 * On Windows, please note the implications of g_shell_parse_argv()
681 * parsing @command_line. Parsing is done according to Unix shell rules, not
682 * Windows command interpreter rules.
683 * Space is a separator, and backslashes are
684 * special. Thus you cannot simply pass a @command_line containing
685 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
686 * the backslashes will be eaten, and the space will act as a
687 * separator. You need to enclose such paths with single quotes, like
688 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
690 * Return value: %TRUE on success, %FALSE if an error was set
693 g_spawn_command_line_sync (const gchar *command_line,
694 gchar **standard_output,
695 gchar **standard_error,
702 g_return_val_if_fail (command_line != NULL, FALSE);
704 if (!g_shell_parse_argv (command_line,
709 retval = g_spawn_sync (NULL,
725 * g_spawn_command_line_async:
726 * @command_line: a command line
727 * @error: return location for errors
729 * A simple version of g_spawn_async() that parses a command line with
730 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
731 * command line in the background. Unlike g_spawn_async(), the
732 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
733 * that %G_SPAWN_SEARCH_PATH can have security implications, so
734 * consider using g_spawn_async() directly if appropriate. Possible
735 * errors are those from g_shell_parse_argv() and g_spawn_async().
737 * The same concerns on Windows apply as for g_spawn_command_line_sync().
739 * Return value: %TRUE on success, %FALSE if error is set.
742 g_spawn_command_line_async (const gchar *command_line,
748 g_return_val_if_fail (command_line != NULL, FALSE);
750 if (!g_shell_parse_argv (command_line,
755 retval = g_spawn_async (NULL,
769 exec_err_to_g_error (gint en)
775 return G_SPAWN_ERROR_ACCES;
781 return G_SPAWN_ERROR_PERM;
787 return G_SPAWN_ERROR_2BIG;
793 return G_SPAWN_ERROR_NOEXEC;
799 return G_SPAWN_ERROR_NAMETOOLONG;
805 return G_SPAWN_ERROR_NOENT;
811 return G_SPAWN_ERROR_NOMEM;
817 return G_SPAWN_ERROR_NOTDIR;
823 return G_SPAWN_ERROR_LOOP;
829 return G_SPAWN_ERROR_TXTBUSY;
835 return G_SPAWN_ERROR_IO;
841 return G_SPAWN_ERROR_NFILE;
847 return G_SPAWN_ERROR_MFILE;
853 return G_SPAWN_ERROR_INVAL;
859 return G_SPAWN_ERROR_ISDIR;
865 return G_SPAWN_ERROR_LIBBAD;
870 return G_SPAWN_ERROR_FAILED;
876 write_all (gint fd, gconstpointer vbuf, gsize to_write)
878 gchar *buf = (gchar *) vbuf;
882 gssize count = write (fd, buf, to_write);
900 write_err_and_exit (gint fd, gint msg)
904 write_all (fd, &msg, sizeof(msg));
905 write_all (fd, &en, sizeof(en));
911 set_cloexec (void *data, gint fd)
913 if (fd >= GPOINTER_TO_INT (data))
914 fcntl (fd, F_SETFD, FD_CLOEXEC);
921 fdwalk (int (*cb)(void *data, int fd), void *data)
927 #ifdef HAVE_SYS_RESOURCE_H
934 if ((d = opendir("/proc/self/fd"))) {
937 while ((de = readdir(d))) {
941 if (de->d_name[0] == '.')
945 l = strtol(de->d_name, &e, 10);
946 if (errno != 0 || !e || *e)
957 if ((res = cb (data, fd)) != 0)
965 /* If /proc is not mounted or not accessible we fall back to the old
970 #ifdef HAVE_SYS_RESOURCE_H
972 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
973 open_max = rl.rlim_max;
976 open_max = sysconf (_SC_OPEN_MAX);
978 for (fd = 0; fd < open_max; fd++)
979 if ((res = cb (data, fd)) != 0)
987 sane_dup2 (gint fd1, gint fd2)
992 ret = dup2 (fd1, fd2);
993 if (ret < 0 && errno == EINTR)
1000 sane_open (const char *path, gint mode)
1005 ret = open (path, mode);
1006 if (ret < 0 && errno == EINTR)
1021 do_exec (gint child_err_report_fd,
1025 const gchar *working_directory,
1028 gboolean close_descriptors,
1029 gboolean search_path,
1030 gboolean stdout_to_null,
1031 gboolean stderr_to_null,
1032 gboolean child_inherits_stdin,
1033 gboolean file_and_argv_zero,
1034 GSpawnChildSetupFunc child_setup,
1037 if (working_directory && chdir (working_directory) < 0)
1038 write_err_and_exit (child_err_report_fd,
1039 CHILD_CHDIR_FAILED);
1041 /* Close all file descriptors but stdin stdout and stderr as
1042 * soon as we exec. Note that this includes
1043 * child_err_report_fd, which keeps the parent from blocking
1044 * forever on the other end of that pipe.
1046 if (close_descriptors)
1048 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1052 /* We need to do child_err_report_fd anyway */
1053 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1056 /* Redirect pipes as required */
1060 /* dup2 can't actually fail here I don't think */
1062 if (sane_dup2 (stdin_fd, 0) < 0)
1063 write_err_and_exit (child_err_report_fd,
1066 /* ignore this if it doesn't work */
1067 close_and_invalidate (&stdin_fd);
1069 else if (!child_inherits_stdin)
1071 /* Keep process from blocking on a read of stdin */
1072 gint read_null = open ("/dev/null", O_RDONLY);
1073 sane_dup2 (read_null, 0);
1074 close_and_invalidate (&read_null);
1079 /* dup2 can't actually fail here I don't think */
1081 if (sane_dup2 (stdout_fd, 1) < 0)
1082 write_err_and_exit (child_err_report_fd,
1085 /* ignore this if it doesn't work */
1086 close_and_invalidate (&stdout_fd);
1088 else if (stdout_to_null)
1090 gint write_null = sane_open ("/dev/null", O_WRONLY);
1091 sane_dup2 (write_null, 1);
1092 close_and_invalidate (&write_null);
1097 /* dup2 can't actually fail here I don't think */
1099 if (sane_dup2 (stderr_fd, 2) < 0)
1100 write_err_and_exit (child_err_report_fd,
1103 /* ignore this if it doesn't work */
1104 close_and_invalidate (&stderr_fd);
1106 else if (stderr_to_null)
1108 gint write_null = sane_open ("/dev/null", O_WRONLY);
1109 sane_dup2 (write_null, 2);
1110 close_and_invalidate (&write_null);
1113 /* Call user function just before we exec */
1116 (* child_setup) (user_data);
1120 file_and_argv_zero ? argv + 1 : argv,
1124 write_err_and_exit (child_err_report_fd,
1141 if (bytes >= sizeof(gint)*2)
1142 break; /* give up, who knows what happened, should not be
1148 ((gchar*)buf) + bytes,
1149 sizeof(gint) * n_ints_in_buf - bytes);
1150 if (chunk < 0 && errno == EINTR)
1157 /* Some weird shit happened, bail out */
1160 G_SPAWN_ERROR_FAILED,
1161 _("Failed to read from child pipe (%s)"),
1162 g_strerror (errsv));
1166 else if (chunk == 0)
1168 else /* chunk > 0 */
1172 *n_ints_read = (gint)(bytes / sizeof(gint));
1178 fork_exec_with_pipes (gboolean intermediate_child,
1179 const gchar *working_directory,
1182 gboolean close_descriptors,
1183 gboolean search_path,
1184 gboolean stdout_to_null,
1185 gboolean stderr_to_null,
1186 gboolean child_inherits_stdin,
1187 gboolean file_and_argv_zero,
1188 GSpawnChildSetupFunc child_setup,
1191 gint *standard_input,
1192 gint *standard_output,
1193 gint *standard_error,
1197 gint stdin_pipe[2] = { -1, -1 };
1198 gint stdout_pipe[2] = { -1, -1 };
1199 gint stderr_pipe[2] = { -1, -1 };
1200 gint child_err_report_pipe[2] = { -1, -1 };
1201 gint child_pid_report_pipe[2] = { -1, -1 };
1204 if (!make_pipe (child_err_report_pipe, error))
1207 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1208 goto cleanup_and_fail;
1210 if (standard_input && !make_pipe (stdin_pipe, error))
1211 goto cleanup_and_fail;
1213 if (standard_output && !make_pipe (stdout_pipe, error))
1214 goto cleanup_and_fail;
1216 if (standard_error && !make_pipe (stderr_pipe, error))
1217 goto cleanup_and_fail;
1228 _("Failed to fork (%s)"),
1229 g_strerror (errsv));
1231 goto cleanup_and_fail;
1235 /* Immediate child. This may or may not be the child that
1236 * actually execs the new process.
1239 /* Reset some signal handlers that we may use */
1240 signal (SIGCHLD, SIG_DFL);
1241 signal (SIGINT, SIG_DFL);
1242 signal (SIGTERM, SIG_DFL);
1243 signal (SIGHUP, SIG_DFL);
1245 /* Be sure we crash if the parent exits
1246 * and we write to the err_report_pipe
1248 signal (SIGPIPE, SIG_DFL);
1250 /* Close the parent's end of the pipes;
1251 * not needed in the close_descriptors case,
1254 close_and_invalidate (&child_err_report_pipe[0]);
1255 close_and_invalidate (&child_pid_report_pipe[0]);
1256 close_and_invalidate (&stdin_pipe[1]);
1257 close_and_invalidate (&stdout_pipe[0]);
1258 close_and_invalidate (&stderr_pipe[0]);
1260 if (intermediate_child)
1262 /* We need to fork an intermediate child that launches the
1263 * final child. The purpose of the intermediate child
1264 * is to exit, so we can waitpid() it immediately.
1265 * Then the grandchild will not become a zombie.
1267 GPid grandchild_pid;
1269 grandchild_pid = fork ();
1271 if (grandchild_pid < 0)
1273 /* report -1 as child PID */
1274 write_all (child_pid_report_pipe[1], &grandchild_pid,
1275 sizeof(grandchild_pid));
1277 write_err_and_exit (child_err_report_pipe[1],
1280 else if (grandchild_pid == 0)
1282 do_exec (child_err_report_pipe[1],
1293 child_inherits_stdin,
1300 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1301 close_and_invalidate (&child_pid_report_pipe[1]);
1308 /* Just run the child.
1311 do_exec (child_err_report_pipe[1],
1322 child_inherits_stdin,
1335 /* Close the uncared-about ends of the pipes */
1336 close_and_invalidate (&child_err_report_pipe[1]);
1337 close_and_invalidate (&child_pid_report_pipe[1]);
1338 close_and_invalidate (&stdin_pipe[0]);
1339 close_and_invalidate (&stdout_pipe[1]);
1340 close_and_invalidate (&stderr_pipe[1]);
1342 /* If we had an intermediate child, reap it */
1343 if (intermediate_child)
1346 if (waitpid (pid, &status, 0) < 0)
1350 else if (errno == ECHILD)
1351 ; /* do nothing, child already reaped */
1353 g_warning ("waitpid() should not fail in "
1354 "'fork_exec_with_pipes'");
1359 if (!read_ints (child_err_report_pipe[0],
1362 goto cleanup_and_fail;
1366 /* Error from the child. */
1370 case CHILD_CHDIR_FAILED:
1373 G_SPAWN_ERROR_CHDIR,
1374 _("Failed to change to directory '%s' (%s)"),
1376 g_strerror (buf[1]));
1380 case CHILD_EXEC_FAILED:
1383 exec_err_to_g_error (buf[1]),
1384 _("Failed to execute child process \"%s\" (%s)"),
1386 g_strerror (buf[1]));
1390 case CHILD_DUP2_FAILED:
1393 G_SPAWN_ERROR_FAILED,
1394 _("Failed to redirect output or input of child process (%s)"),
1395 g_strerror (buf[1]));
1399 case CHILD_FORK_FAILED:
1403 _("Failed to fork child process (%s)"),
1404 g_strerror (buf[1]));
1410 G_SPAWN_ERROR_FAILED,
1411 _("Unknown error executing child process \"%s\""),
1416 goto cleanup_and_fail;
1419 /* Get child pid from intermediate child pipe. */
1420 if (intermediate_child)
1424 if (!read_ints (child_pid_report_pipe[0],
1425 buf, 1, &n_ints, error))
1426 goto cleanup_and_fail;
1434 G_SPAWN_ERROR_FAILED,
1435 _("Failed to read enough data from child pid pipe (%s)"),
1436 g_strerror (errsv));
1437 goto cleanup_and_fail;
1441 /* we have the child pid */
1446 /* Success against all odds! return the information */
1447 close_and_invalidate (&child_err_report_pipe[0]);
1448 close_and_invalidate (&child_pid_report_pipe[0]);
1454 *standard_input = stdin_pipe[1];
1455 if (standard_output)
1456 *standard_output = stdout_pipe[0];
1458 *standard_error = stderr_pipe[0];
1465 /* There was an error from the Child, reap the child to avoid it being
1472 if (waitpid (pid, NULL, 0) < 0)
1476 else if (errno == ECHILD)
1477 ; /* do nothing, child already reaped */
1479 g_warning ("waitpid() should not fail in "
1480 "'fork_exec_with_pipes'");
1484 close_and_invalidate (&child_err_report_pipe[0]);
1485 close_and_invalidate (&child_err_report_pipe[1]);
1486 close_and_invalidate (&child_pid_report_pipe[0]);
1487 close_and_invalidate (&child_pid_report_pipe[1]);
1488 close_and_invalidate (&stdin_pipe[0]);
1489 close_and_invalidate (&stdin_pipe[1]);
1490 close_and_invalidate (&stdout_pipe[0]);
1491 close_and_invalidate (&stdout_pipe[1]);
1492 close_and_invalidate (&stderr_pipe[0]);
1493 close_and_invalidate (&stderr_pipe[1]);
1499 make_pipe (gint p[2],
1507 G_SPAWN_ERROR_FAILED,
1508 _("Failed to create pipe for communicating with child process (%s)"),
1509 g_strerror (errsv));
1516 /* Based on execvp from GNU C Library */
1519 script_execute (const gchar *file,
1522 gboolean search_path)
1524 /* Count the arguments. */
1529 /* Construct an argument list for the shell. */
1533 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1535 new_argv[0] = (char *) "/bin/sh";
1536 new_argv[1] = (char *) file;
1539 new_argv[argc + 1] = argv[argc];
1543 /* Execute the shell. */
1545 execve (new_argv[0], new_argv, envp);
1547 execv (new_argv[0], new_argv);
1554 my_strchrnul (const gchar *str, gchar c)
1556 gchar *p = (gchar*) str;
1557 while (*p && (*p != c))
1564 g_execute (const gchar *file,
1567 gboolean search_path)
1571 /* We check the simple case first. */
1576 if (!search_path || strchr (file, '/') != NULL)
1578 /* Don't search when it contains a slash. */
1580 execve (file, argv, envp);
1584 if (errno == ENOEXEC)
1585 script_execute (file, argv, envp, FALSE);
1589 gboolean got_eacces = 0;
1590 const gchar *path, *p;
1591 gchar *name, *freeme;
1595 path = g_getenv ("PATH");
1598 /* There is no `PATH' in the environment. The default
1599 * search path in libc is the current directory followed by
1600 * the path `confstr' returns for `_CS_PATH'.
1603 /* In GLib we put . last, for security, and don't use the
1604 * unportable confstr(); UNIX98 does not actually specify
1605 * what to search if PATH is unset. POSIX may, dunno.
1608 path = "/bin:/usr/bin:.";
1611 len = strlen (file) + 1;
1612 pathlen = strlen (path);
1613 freeme = name = g_malloc (pathlen + len + 1);
1615 /* Copy the file name at the top, including '\0' */
1616 memcpy (name + pathlen + 1, file, len);
1617 name = name + pathlen;
1618 /* And add the slash before the filename */
1627 p = my_strchrnul (path, ':');
1630 /* Two adjacent colons, or a colon at the beginning or the end
1631 * of `PATH' means to search the current directory.
1635 startp = memcpy (name - (p - path), path, p - path);
1637 /* Try to execute this name. If it works, execv will not return. */
1639 execve (startp, argv, envp);
1641 execv (startp, argv);
1643 if (errno == ENOEXEC)
1644 script_execute (startp, argv, envp, search_path);
1649 /* Record the we got a `Permission denied' error. If we end
1650 * up finding no executable we can use, we want to diagnose
1651 * that we did find one but were denied access.
1664 /* Those errors indicate the file is missing or not executable
1665 * by us, in which case we want to just try the next path
1671 /* Some other error means we found an executable file, but
1672 * something went wrong executing it; return the error to our
1679 while (*p++ != '\0');
1681 /* We tried every element and none of them worked. */
1683 /* At least one failure was due to permissions, so report that
1691 /* Return the error from the last attempt (probably ENOENT). */
1696 * g_spawn_close_pid:
1697 * @pid: The process reference to close
1699 * On some platforms, notably Windows, the #GPid type represents a resource
1700 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1701 * is provided for this purpose. It should be used on all platforms, even
1702 * though it doesn't do anything under UNIX.
1705 g_spawn_close_pid (GPid pid)