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 */
46 #include "glib/gstdio.h"
52 #include "gstrfuncs.h"
53 #include "gtestutils.h"
56 #include "glib-unix.h"
60 * @Short_description: process launching
61 * @Title: Spawning Processes
66 static gint g_execute (const gchar *file,
70 gboolean search_path_from_envp);
72 static gboolean fork_exec_with_pipes (gboolean intermediate_child,
73 const gchar *working_directory,
76 gboolean close_descriptors,
78 gboolean search_path_from_envp,
79 gboolean stdout_to_null,
80 gboolean stderr_to_null,
81 gboolean child_inherits_stdin,
82 gboolean file_and_argv_zero,
83 gboolean cloexec_pipes,
84 GSpawnChildSetupFunc child_setup,
88 gint *standard_output,
92 G_DEFINE_QUARK (g-exec-error-quark, g_spawn_error)
93 G_DEFINE_QUARK (g-spawn-exit-error-quark, g_spawn_exit_error)
97 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
98 * @argv: (array zero-terminated=1): child's argument vector
99 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
100 * @flags: flags from #GSpawnFlags
101 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
102 * @user_data: (closure): user data for @child_setup
103 * @child_pid: (out) (allow-none): return location for child process reference, or %NULL
104 * @error: return location for error
106 * See g_spawn_async_with_pipes() for a full description; this function
107 * simply calls the g_spawn_async_with_pipes() without any pipes.
109 * You should call g_spawn_close_pid() on the returned child process
110 * reference when you don't need it any more.
112 * If you are writing a GTK+ application, and the program you are
113 * spawning is a graphical application, too, then you may want to
114 * use gdk_spawn_on_screen() instead to ensure that the spawned program
115 * opens its windows on the right screen.
117 * Note that the returned @child_pid on Windows is a handle to the child
118 * process and not its identifier. Process handles and process identifiers
119 * are different concepts on Windows.
121 * Return value: %TRUE on success, %FALSE if error is set
124 g_spawn_async (const gchar *working_directory,
128 GSpawnChildSetupFunc child_setup,
133 g_return_val_if_fail (argv != NULL, FALSE);
135 return g_spawn_async_with_pipes (working_directory,
145 /* Avoids a danger in threaded situations (calling close()
146 * on a file descriptor twice, and another thread has
147 * re-opened it since the first close)
150 close_and_invalidate (gint *fd)
156 (void) g_close (*fd, NULL);
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.
224 * If @exit_status is non-%NULL, the platform-specific exit status of
225 * the child is stored there; see the documentation of
226 * g_spawn_check_exit_status() for how to use and interpret this.
227 * Note that it is invalid to pass %G_SPAWN_DO_NOT_REAP_CHILD in
230 * If an error occurs, no data is returned in @standard_output,
231 * @standard_error, or @exit_status.
233 * This function calls g_spawn_async_with_pipes() internally; see that
234 * function for full details on the other parameters and details on
235 * how these functions work on Windows.
237 * Return value: %TRUE on success, %FALSE if an error was set
240 g_spawn_sync (const gchar *working_directory,
244 GSpawnChildSetupFunc child_setup,
246 gchar **standard_output,
247 gchar **standard_error,
256 GString *outstr = NULL;
257 GString *errstr = NULL;
261 g_return_val_if_fail (argv != NULL, FALSE);
262 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
263 g_return_val_if_fail (standard_output == NULL ||
264 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
265 g_return_val_if_fail (standard_error == NULL ||
266 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
268 /* Just to ensure segfaults if callers try to use
269 * these when an error is reported.
272 *standard_output = NULL;
275 *standard_error = NULL;
277 if (!fork_exec_with_pipes (FALSE,
281 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
282 (flags & G_SPAWN_SEARCH_PATH) != 0,
283 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
284 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
285 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
286 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
287 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
288 (flags & G_SPAWN_CLOEXEC_PIPES) != 0,
293 standard_output ? &outpipe : NULL,
294 standard_error ? &errpipe : NULL,
298 /* Read data from child. */
304 outstr = g_string_new (NULL);
309 errstr = g_string_new (NULL);
312 /* Read data until we get EOF on both pipes. */
321 FD_SET (outpipe, &fds);
323 FD_SET (errpipe, &fds);
325 ret = select (MAX (outpipe, errpipe) + 1,
328 NULL /* no timeout */);
342 _("Unexpected error in select() reading data from a child process (%s)"),
348 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
350 switch (read_data (outstr, outpipe, error))
356 close_and_invalidate (&outpipe);
367 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
369 switch (read_data (errstr, errpipe, error))
375 close_and_invalidate (&errpipe);
387 /* These should only be open still if we had an error. */
390 close_and_invalidate (&outpipe);
392 close_and_invalidate (&errpipe);
394 /* Wait for child to exit, even if we have
399 ret = waitpid (pid, &status, 0);
405 else if (errno == ECHILD)
409 g_warning ("In call to g_spawn_sync(), exit status of a child process was requested but ECHILD was received by waitpid(). Most likely the process is ignoring SIGCHLD, or some other thread is invoking waitpid() with a nonpositive first argument; either behavior can break applications that use g_spawn_sync either directly or indirectly.");
413 /* We don't need the exit status. */
418 if (!failed) /* avoid error pileups */
427 _("Unexpected error in waitpid() (%s)"),
436 g_string_free (outstr, TRUE);
438 g_string_free (errstr, TRUE);
445 *exit_status = status;
448 *standard_output = g_string_free (outstr, FALSE);
451 *standard_error = g_string_free (errstr, FALSE);
458 * g_spawn_async_with_pipes:
459 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
460 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
461 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
462 * @flags: flags from #GSpawnFlags
463 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
464 * @user_data: (closure): user data for @child_setup
465 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
466 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
467 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
468 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
469 * @error: return location for error
471 * Executes a child program asynchronously (your program will not
472 * block waiting for the child to exit). The child program is
473 * specified by the only argument that must be provided, @argv. @argv
474 * should be a %NULL-terminated array of strings, to be passed as the
475 * argument vector for the child. The first string in @argv is of
476 * course the name of the program to execute. By default, the name of
477 * the program must be a full path. If @flags contains the
478 * %G_SPAWN_SEARCH_PATH flag, the <envar>PATH</envar> environment variable
479 * is used to search for the executable. If @flags contains the
480 * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the <envar>PATH</envar> variable from
481 * @envp is used to search for the executable.
482 * If both the %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP
483 * flags are set, the <envar>PATH</envar> variable from @envp takes precedence
484 * over the environment variable.
486 * If the program name is not a full path and %G_SPAWN_SEARCH_PATH flag is not
487 * used, then the program will be run from the current directory (or
488 * @working_directory, if specified); this might be unexpected or even
489 * dangerous in some cases when the current directory is world-writable.
491 * On Windows, note that all the string or string vector arguments to
492 * this function and the other g_spawn*() functions are in UTF-8, the
493 * GLib file name encoding. Unicode characters that are not part of
494 * the system codepage passed in these arguments will be correctly
495 * available in the spawned program only if it uses wide character API
496 * to retrieve its command line. For C programs built with Microsoft's
497 * tools it is enough to make the program have a wmain() instead of
498 * main(). wmain() has a wide character argument vector as parameter.
500 * At least currently, mingw doesn't support wmain(), so if you use
501 * mingw to develop the spawned program, it will have to call the
502 * undocumented function __wgetmainargs() to get the wide character
503 * argument vector and environment. See gspawn-win32-helper.c in the
504 * GLib sources or init.c in the mingw runtime sources for a prototype
505 * for that function. Alternatively, you can retrieve the Win32 system
506 * level wide character command line passed to the spawned program
507 * using the GetCommandLineW() function.
509 * On Windows the low-level child process creation API CreateProcess()
510 * doesn't use argument vectors, but a command line. The C runtime
511 * library's spawn*() family of functions (which g_spawn_async_with_pipes()
512 * eventually calls) paste the argument vector elements together into
513 * a command line, and the C runtime startup code does a corresponding
514 * reconstruction of an argument vector from the command line, to be
515 * passed to main(). Complications arise when you have argument vector
516 * elements that contain spaces of double quotes. The spawn*() functions
517 * don't do any quoting or escaping, but on the other hand the startup
518 * code does do unquoting and unescaping in order to enable receiving
519 * arguments with embedded spaces or double quotes. To work around this
520 * asymmetry, g_spawn_async_with_pipes() will do quoting and escaping on
521 * argument vector elements that need it before calling the C runtime
524 * The returned @child_pid on Windows is a handle to the child
525 * process, not its identifier. Process handles and process
526 * identifiers are different concepts on Windows.
528 * @envp is a %NULL-terminated array of strings, where each string
529 * has the form <literal>KEY=VALUE</literal>. This will become
530 * the child's environment. If @envp is %NULL, the child inherits its
531 * parent's environment.
533 * @flags should be the bitwise OR of any flags you want to affect the
534 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that the
535 * child will not automatically be reaped; you must use a child watch to
536 * be notified about the death of the child process. Eventually you must
537 * call g_spawn_close_pid() on the @child_pid, in order to free
538 * resources which may be associated with the child process. (On Unix,
539 * using a child watch is equivalent to calling waitpid() or handling
540 * the %SIGCHLD signal manually. On Windows, calling g_spawn_close_pid()
541 * is equivalent to calling CloseHandle() on the process handle returned
542 * in @child_pid). See g_child_watch_add().
544 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
545 * descriptors will be inherited by the child; otherwise all descriptors
546 * except stdin/stdout/stderr will be closed before calling exec() in the
547 * child. %G_SPAWN_SEARCH_PATH means that @argv[0] need not be an absolute
548 * path, it will be looked for in the <envar>PATH</envar> environment
549 * variable. %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an absolute
550 * path, it will be looked for in the <envar>PATH</envar> variable from
551 * @envp. If both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP
552 * are used, the value from @envp takes precedence over the environment.
553 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
554 * be discarded, instead of going to the same location as the parent's
555 * standard output. If you use this flag, @standard_output must be %NULL.
556 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
557 * will be discarded, instead of going to the same location as the parent's
558 * standard error. If you use this flag, @standard_error must be %NULL.
559 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
560 * standard input (by default, the child's standard input is attached to
561 * /dev/null). If you use this flag, @standard_input must be %NULL.
562 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
563 * the file to execute, while the remaining elements are the actual
564 * argument vector to pass to the file. Normally g_spawn_async_with_pipes()
565 * uses @argv[0] as the file to execute, and passes all of @argv to the child.
567 * @child_setup and @user_data are a function and user data. On POSIX
568 * platforms, the function is called in the child after GLib has
569 * performed all the setup it plans to perform (including creating
570 * pipes, closing file descriptors, etc.) but before calling exec().
571 * That is, @child_setup is called just before calling exec() in the
572 * child. Obviously actions taken in this function will only affect
573 * the child, not the parent.
575 * On Windows, there is no separate fork() and exec() functionality.
576 * Child processes are created and run with a single API call,
577 * CreateProcess(). There is no sensible thing @child_setup
578 * could be used for on Windows so it is ignored and not called.
580 * If non-%NULL, @child_pid will on Unix be filled with the child's
581 * process ID. You can use the process ID to send signals to the child,
582 * or to use g_child_watch_add() (or waitpid()) if you specified the
583 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
584 * filled with a handle to the child process only if you specified the
585 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
586 * process using the Win32 API, for example wait for its termination
587 * with the WaitFor*() functions, or examine its exit code with
588 * GetExitCodeProcess(). You should close the handle with CloseHandle()
589 * or g_spawn_close_pid() when you no longer need it.
591 * If non-%NULL, the @standard_input, @standard_output, @standard_error
592 * locations will be filled with file descriptors for writing to the child's
593 * standard input or reading from its standard output or standard error.
594 * The caller of g_spawn_async_with_pipes() must close these file descriptors
595 * when they are no longer in use. If these parameters are %NULL, the
596 * corresponding pipe won't be created.
598 * If @standard_input is NULL, the child's standard input is attached to
599 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
601 * If @standard_error is NULL, the child's standard error goes to the same
602 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
605 * If @standard_output is NULL, the child's standard output goes to the same
606 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
609 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
610 * If an error is set, the function returns %FALSE. Errors are reported
611 * even if they occur in the child (for example if the executable in
612 * @argv[0] is not found). Typically the <literal>message</literal> field
613 * of returned errors should be displayed to users. Possible errors are
614 * those from the #G_SPAWN_ERROR domain.
616 * If an error occurs, @child_pid, @standard_input, @standard_output,
617 * and @standard_error will not be filled with valid values.
619 * If @child_pid is not %NULL and an error does not occur then the returned
620 * process reference must be closed using g_spawn_close_pid().
622 * If you are writing a GTK+ application, and the program you
623 * are spawning is a graphical application, too, then you may
624 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
625 * the spawned program opens its windows on the right screen.
627 * Return value: %TRUE on success, %FALSE if an error was set
630 g_spawn_async_with_pipes (const gchar *working_directory,
634 GSpawnChildSetupFunc child_setup,
637 gint *standard_input,
638 gint *standard_output,
639 gint *standard_error,
642 g_return_val_if_fail (argv != NULL, FALSE);
643 g_return_val_if_fail (standard_output == NULL ||
644 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
645 g_return_val_if_fail (standard_error == NULL ||
646 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
647 /* can't inherit stdin if we have an input pipe. */
648 g_return_val_if_fail (standard_input == NULL ||
649 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
651 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
655 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
656 (flags & G_SPAWN_SEARCH_PATH) != 0,
657 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
658 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
659 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
660 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
661 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
662 (flags & G_SPAWN_CLOEXEC_PIPES) != 0,
673 * g_spawn_command_line_sync:
674 * @command_line: a command line
675 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
676 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
677 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
678 * @error: return location for errors
680 * A simple version of g_spawn_sync() with little-used parameters
681 * removed, taking a command line instead of an argument vector. See
682 * g_spawn_sync() for full details. @command_line will be parsed by
683 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
684 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
685 * implications, so consider using g_spawn_sync() directly if
686 * appropriate. Possible errors are those from g_spawn_sync() and those
687 * from g_shell_parse_argv().
689 * If @exit_status is non-%NULL, the platform-specific exit status of
690 * the child is stored there; see the documentation of
691 * g_spawn_check_exit_status() for how to use and interpret this.
693 * On Windows, please note the implications of g_shell_parse_argv()
694 * parsing @command_line. Parsing is done according to Unix shell rules, not
695 * Windows command interpreter rules.
696 * Space is a separator, and backslashes are
697 * special. Thus you cannot simply pass a @command_line containing
698 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
699 * the backslashes will be eaten, and the space will act as a
700 * separator. You need to enclose such paths with single quotes, like
701 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
703 * Return value: %TRUE on success, %FALSE if an error was set
706 g_spawn_command_line_sync (const gchar *command_line,
707 gchar **standard_output,
708 gchar **standard_error,
715 g_return_val_if_fail (command_line != NULL, FALSE);
717 if (!g_shell_parse_argv (command_line,
722 retval = g_spawn_sync (NULL,
738 * g_spawn_command_line_async:
739 * @command_line: a command line
740 * @error: return location for errors
742 * A simple version of g_spawn_async() that parses a command line with
743 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
744 * command line in the background. Unlike g_spawn_async(), the
745 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
746 * that %G_SPAWN_SEARCH_PATH can have security implications, so
747 * consider using g_spawn_async() directly if appropriate. Possible
748 * errors are those from g_shell_parse_argv() and g_spawn_async().
750 * The same concerns on Windows apply as for g_spawn_command_line_sync().
752 * Return value: %TRUE on success, %FALSE if error is set
755 g_spawn_command_line_async (const gchar *command_line,
761 g_return_val_if_fail (command_line != NULL, FALSE);
763 if (!g_shell_parse_argv (command_line,
768 retval = g_spawn_async (NULL,
782 * g_spawn_check_exit_status:
783 * @exit_status: An exit code as returned from g_spawn_sync()
786 * Set @error if @exit_status indicates the child exited abnormally
787 * (e.g. with a nonzero exit code, or via a fatal signal).
789 * The g_spawn_sync() and g_child_watch_add() family of APIs return an
790 * exit status for subprocesses encoded in a platform-specific way.
791 * On Unix, this is guaranteed to be in the same format waitpid() returns,
792 * and on Windows it is guaranteed to be the result of GetExitCodeProcess().
794 * Prior to the introduction of this function in GLib 2.34, interpreting
795 * @exit_status required use of platform-specific APIs, which is problematic
796 * for software using GLib as a cross-platform layer.
798 * Additionally, many programs simply want to determine whether or not
799 * the child exited successfully, and either propagate a #GError or
800 * print a message to standard error. In that common case, this function
801 * can be used. Note that the error message in @error will contain
802 * human-readable information about the exit status.
804 * The @domain and @code of @error have special semantics in the case
805 * where the process has an "exit code", as opposed to being killed by
806 * a signal. On Unix, this happens if WIFEXITED() would be true of
807 * @exit_status. On Windows, it is always the case.
809 * The special semantics are that the actual exit code will be the
810 * code set in @error, and the domain will be %G_SPAWN_EXIT_ERROR.
811 * This allows you to differentiate between different exit codes.
813 * If the process was terminated by some means other than an exit
814 * status, the domain will be %G_SPAWN_ERROR, and the code will be
815 * %G_SPAWN_ERROR_FAILED.
817 * This function just offers convenience; you can of course also check
818 * the available platform via a macro such as %G_OS_UNIX, and use
819 * WIFEXITED() and WEXITSTATUS() on @exit_status directly. Do not attempt
820 * to scan or parse the error message string; it may be translated and/or
821 * change in future versions of GLib.
823 * Returns: %TRUE if child exited successfully, %FALSE otherwise (and
824 * @error will be set)
829 g_spawn_check_exit_status (gint exit_status,
832 gboolean ret = FALSE;
834 if (WIFEXITED (exit_status))
836 if (WEXITSTATUS (exit_status) != 0)
838 g_set_error (error, G_SPAWN_EXIT_ERROR, WEXITSTATUS (exit_status),
839 _("Child process exited with code %ld"),
840 (long) WEXITSTATUS (exit_status));
844 else if (WIFSIGNALED (exit_status))
846 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
847 _("Child process killed by signal %ld"),
848 (long) WTERMSIG (exit_status));
851 else if (WIFSTOPPED (exit_status))
853 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
854 _("Child process stopped by signal %ld"),
855 (long) WSTOPSIG (exit_status));
860 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
861 _("Child process exited abnormally"));
871 exec_err_to_g_error (gint en)
877 return G_SPAWN_ERROR_ACCES;
883 return G_SPAWN_ERROR_PERM;
889 return G_SPAWN_ERROR_TOO_BIG;
895 return G_SPAWN_ERROR_NOEXEC;
901 return G_SPAWN_ERROR_NAMETOOLONG;
907 return G_SPAWN_ERROR_NOENT;
913 return G_SPAWN_ERROR_NOMEM;
919 return G_SPAWN_ERROR_NOTDIR;
925 return G_SPAWN_ERROR_LOOP;
931 return G_SPAWN_ERROR_TXTBUSY;
937 return G_SPAWN_ERROR_IO;
943 return G_SPAWN_ERROR_NFILE;
949 return G_SPAWN_ERROR_MFILE;
955 return G_SPAWN_ERROR_INVAL;
961 return G_SPAWN_ERROR_ISDIR;
967 return G_SPAWN_ERROR_LIBBAD;
972 return G_SPAWN_ERROR_FAILED;
978 write_all (gint fd, gconstpointer vbuf, gsize to_write)
980 gchar *buf = (gchar *) vbuf;
984 gssize count = write (fd, buf, to_write);
1002 write_err_and_exit (gint fd, gint msg)
1006 write_all (fd, &msg, sizeof(msg));
1007 write_all (fd, &en, sizeof(en));
1013 set_cloexec (void *data, gint fd)
1015 if (fd >= GPOINTER_TO_INT (data))
1016 fcntl (fd, F_SETFD, FD_CLOEXEC);
1023 fdwalk (int (*cb)(void *data, int fd), void *data)
1029 #ifdef HAVE_SYS_RESOURCE_H
1036 if ((d = opendir("/proc/self/fd"))) {
1039 while ((de = readdir(d))) {
1043 if (de->d_name[0] == '.')
1047 l = strtol(de->d_name, &e, 10);
1048 if (errno != 0 || !e || *e)
1053 if ((glong) fd != l)
1059 if ((res = cb (data, fd)) != 0)
1067 /* If /proc is not mounted or not accessible we fall back to the old
1072 #ifdef HAVE_SYS_RESOURCE_H
1074 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
1075 open_max = rl.rlim_max;
1078 open_max = sysconf (_SC_OPEN_MAX);
1080 for (fd = 0; fd < open_max; fd++)
1081 if ((res = cb (data, fd)) != 0)
1089 sane_dup2 (gint fd1, gint fd2)
1094 ret = dup2 (fd1, fd2);
1095 if (ret < 0 && errno == EINTR)
1102 sane_open (const char *path, gint mode)
1107 ret = open (path, mode);
1108 if (ret < 0 && errno == EINTR)
1123 do_exec (gint child_err_report_fd,
1127 const gchar *working_directory,
1130 gboolean close_descriptors,
1131 gboolean search_path,
1132 gboolean search_path_from_envp,
1133 gboolean stdout_to_null,
1134 gboolean stderr_to_null,
1135 gboolean child_inherits_stdin,
1136 gboolean file_and_argv_zero,
1137 GSpawnChildSetupFunc child_setup,
1140 if (working_directory && chdir (working_directory) < 0)
1141 write_err_and_exit (child_err_report_fd,
1142 CHILD_CHDIR_FAILED);
1144 /* Close all file descriptors but stdin stdout and stderr as
1145 * soon as we exec. Note that this includes
1146 * child_err_report_fd, which keeps the parent from blocking
1147 * forever on the other end of that pipe.
1149 if (close_descriptors)
1151 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1155 /* We need to do child_err_report_fd anyway */
1156 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1159 /* Redirect pipes as required */
1163 /* dup2 can't actually fail here I don't think */
1165 if (sane_dup2 (stdin_fd, 0) < 0)
1166 write_err_and_exit (child_err_report_fd,
1169 /* ignore this if it doesn't work */
1170 close_and_invalidate (&stdin_fd);
1172 else if (!child_inherits_stdin)
1174 /* Keep process from blocking on a read of stdin */
1175 gint read_null = open ("/dev/null", O_RDONLY);
1176 g_assert (read_null != -1);
1177 sane_dup2 (read_null, 0);
1178 close_and_invalidate (&read_null);
1183 /* dup2 can't actually fail here I don't think */
1185 if (sane_dup2 (stdout_fd, 1) < 0)
1186 write_err_and_exit (child_err_report_fd,
1189 /* ignore this if it doesn't work */
1190 close_and_invalidate (&stdout_fd);
1192 else if (stdout_to_null)
1194 gint write_null = sane_open ("/dev/null", O_WRONLY);
1195 g_assert (write_null != -1);
1196 sane_dup2 (write_null, 1);
1197 close_and_invalidate (&write_null);
1202 /* dup2 can't actually fail here I don't think */
1204 if (sane_dup2 (stderr_fd, 2) < 0)
1205 write_err_and_exit (child_err_report_fd,
1208 /* ignore this if it doesn't work */
1209 close_and_invalidate (&stderr_fd);
1211 else if (stderr_to_null)
1213 gint write_null = sane_open ("/dev/null", O_WRONLY);
1214 sane_dup2 (write_null, 2);
1215 close_and_invalidate (&write_null);
1218 /* Call user function just before we exec */
1221 (* child_setup) (user_data);
1225 file_and_argv_zero ? argv + 1 : argv,
1226 envp, search_path, search_path_from_envp);
1229 write_err_and_exit (child_err_report_fd,
1246 if (bytes >= sizeof(gint)*2)
1247 break; /* give up, who knows what happened, should not be
1253 ((gchar*)buf) + bytes,
1254 sizeof(gint) * n_ints_in_buf - bytes);
1255 if (chunk < 0 && errno == EINTR)
1262 /* Some weird shit happened, bail out */
1265 G_SPAWN_ERROR_FAILED,
1266 _("Failed to read from child pipe (%s)"),
1267 g_strerror (errsv));
1271 else if (chunk == 0)
1273 else /* chunk > 0 */
1277 *n_ints_read = (gint)(bytes / sizeof(gint));
1283 fork_exec_with_pipes (gboolean intermediate_child,
1284 const gchar *working_directory,
1287 gboolean close_descriptors,
1288 gboolean search_path,
1289 gboolean search_path_from_envp,
1290 gboolean stdout_to_null,
1291 gboolean stderr_to_null,
1292 gboolean child_inherits_stdin,
1293 gboolean file_and_argv_zero,
1294 gboolean cloexec_pipes,
1295 GSpawnChildSetupFunc child_setup,
1298 gint *standard_input,
1299 gint *standard_output,
1300 gint *standard_error,
1304 gint stdin_pipe[2] = { -1, -1 };
1305 gint stdout_pipe[2] = { -1, -1 };
1306 gint stderr_pipe[2] = { -1, -1 };
1307 gint child_err_report_pipe[2] = { -1, -1 };
1308 gint child_pid_report_pipe[2] = { -1, -1 };
1309 guint pipe_flags = cloexec_pipes ? FD_CLOEXEC : 0;
1312 if (!g_unix_open_pipe (child_err_report_pipe, pipe_flags, error))
1315 if (intermediate_child && !g_unix_open_pipe (child_pid_report_pipe, pipe_flags, error))
1316 goto cleanup_and_fail;
1318 if (standard_input && !g_unix_open_pipe (stdin_pipe, pipe_flags, error))
1319 goto cleanup_and_fail;
1321 if (standard_output && !g_unix_open_pipe (stdout_pipe, pipe_flags, error))
1322 goto cleanup_and_fail;
1324 if (standard_error && !g_unix_open_pipe (stderr_pipe, FD_CLOEXEC, error))
1325 goto cleanup_and_fail;
1336 _("Failed to fork (%s)"),
1337 g_strerror (errsv));
1339 goto cleanup_and_fail;
1343 /* Immediate child. This may or may not be the child that
1344 * actually execs the new process.
1347 /* Reset some signal handlers that we may use */
1348 signal (SIGCHLD, SIG_DFL);
1349 signal (SIGINT, SIG_DFL);
1350 signal (SIGTERM, SIG_DFL);
1351 signal (SIGHUP, SIG_DFL);
1353 /* Be sure we crash if the parent exits
1354 * and we write to the err_report_pipe
1356 signal (SIGPIPE, SIG_DFL);
1358 /* Close the parent's end of the pipes;
1359 * not needed in the close_descriptors case,
1362 close_and_invalidate (&child_err_report_pipe[0]);
1363 close_and_invalidate (&child_pid_report_pipe[0]);
1364 close_and_invalidate (&stdin_pipe[1]);
1365 close_and_invalidate (&stdout_pipe[0]);
1366 close_and_invalidate (&stderr_pipe[0]);
1368 if (intermediate_child)
1370 /* We need to fork an intermediate child that launches the
1371 * final child. The purpose of the intermediate child
1372 * is to exit, so we can waitpid() it immediately.
1373 * Then the grandchild will not become a zombie.
1375 GPid grandchild_pid;
1377 grandchild_pid = fork ();
1379 if (grandchild_pid < 0)
1381 /* report -1 as child PID */
1382 write_all (child_pid_report_pipe[1], &grandchild_pid,
1383 sizeof(grandchild_pid));
1385 write_err_and_exit (child_err_report_pipe[1],
1388 else if (grandchild_pid == 0)
1390 close_and_invalidate (&child_pid_report_pipe[1]);
1391 do_exec (child_err_report_pipe[1],
1400 search_path_from_envp,
1403 child_inherits_stdin,
1410 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1411 close_and_invalidate (&child_pid_report_pipe[1]);
1418 /* Just run the child.
1421 do_exec (child_err_report_pipe[1],
1430 search_path_from_envp,
1433 child_inherits_stdin,
1446 /* Close the uncared-about ends of the pipes */
1447 close_and_invalidate (&child_err_report_pipe[1]);
1448 close_and_invalidate (&child_pid_report_pipe[1]);
1449 close_and_invalidate (&stdin_pipe[0]);
1450 close_and_invalidate (&stdout_pipe[1]);
1451 close_and_invalidate (&stderr_pipe[1]);
1453 /* If we had an intermediate child, reap it */
1454 if (intermediate_child)
1457 if (waitpid (pid, &status, 0) < 0)
1461 else if (errno == ECHILD)
1462 ; /* do nothing, child already reaped */
1464 g_warning ("waitpid() should not fail in "
1465 "'fork_exec_with_pipes'");
1470 if (!read_ints (child_err_report_pipe[0],
1473 goto cleanup_and_fail;
1477 /* Error from the child. */
1481 case CHILD_CHDIR_FAILED:
1484 G_SPAWN_ERROR_CHDIR,
1485 _("Failed to change to directory '%s' (%s)"),
1487 g_strerror (buf[1]));
1491 case CHILD_EXEC_FAILED:
1494 exec_err_to_g_error (buf[1]),
1495 _("Failed to execute child process \"%s\" (%s)"),
1497 g_strerror (buf[1]));
1501 case CHILD_DUP2_FAILED:
1504 G_SPAWN_ERROR_FAILED,
1505 _("Failed to redirect output or input of child process (%s)"),
1506 g_strerror (buf[1]));
1510 case CHILD_FORK_FAILED:
1514 _("Failed to fork child process (%s)"),
1515 g_strerror (buf[1]));
1521 G_SPAWN_ERROR_FAILED,
1522 _("Unknown error executing child process \"%s\""),
1527 goto cleanup_and_fail;
1530 /* Get child pid from intermediate child pipe. */
1531 if (intermediate_child)
1535 if (!read_ints (child_pid_report_pipe[0],
1536 buf, 1, &n_ints, error))
1537 goto cleanup_and_fail;
1545 G_SPAWN_ERROR_FAILED,
1546 _("Failed to read enough data from child pid pipe (%s)"),
1547 g_strerror (errsv));
1548 goto cleanup_and_fail;
1552 /* we have the child pid */
1557 /* Success against all odds! return the information */
1558 close_and_invalidate (&child_err_report_pipe[0]);
1559 close_and_invalidate (&child_pid_report_pipe[0]);
1565 *standard_input = stdin_pipe[1];
1566 if (standard_output)
1567 *standard_output = stdout_pipe[0];
1569 *standard_error = stderr_pipe[0];
1576 /* There was an error from the Child, reap the child to avoid it being
1583 if (waitpid (pid, NULL, 0) < 0)
1587 else if (errno == ECHILD)
1588 ; /* do nothing, child already reaped */
1590 g_warning ("waitpid() should not fail in "
1591 "'fork_exec_with_pipes'");
1595 close_and_invalidate (&child_err_report_pipe[0]);
1596 close_and_invalidate (&child_err_report_pipe[1]);
1597 close_and_invalidate (&child_pid_report_pipe[0]);
1598 close_and_invalidate (&child_pid_report_pipe[1]);
1599 close_and_invalidate (&stdin_pipe[0]);
1600 close_and_invalidate (&stdin_pipe[1]);
1601 close_and_invalidate (&stdout_pipe[0]);
1602 close_and_invalidate (&stdout_pipe[1]);
1603 close_and_invalidate (&stderr_pipe[0]);
1604 close_and_invalidate (&stderr_pipe[1]);
1609 /* Based on execvp from GNU C Library */
1612 script_execute (const gchar *file,
1616 /* Count the arguments. */
1621 /* Construct an argument list for the shell. */
1625 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1627 new_argv[0] = (char *) "/bin/sh";
1628 new_argv[1] = (char *) file;
1631 new_argv[argc + 1] = argv[argc];
1635 /* Execute the shell. */
1637 execve (new_argv[0], new_argv, envp);
1639 execv (new_argv[0], new_argv);
1646 my_strchrnul (const gchar *str, gchar c)
1648 gchar *p = (gchar*) str;
1649 while (*p && (*p != c))
1656 g_execute (const gchar *file,
1659 gboolean search_path,
1660 gboolean search_path_from_envp)
1664 /* We check the simple case first. */
1669 if (!(search_path || search_path_from_envp) || strchr (file, '/') != NULL)
1671 /* Don't search when it contains a slash. */
1673 execve (file, argv, envp);
1677 if (errno == ENOEXEC)
1678 script_execute (file, argv, envp);
1682 gboolean got_eacces = 0;
1683 const gchar *path, *p;
1684 gchar *name, *freeme;
1689 if (search_path_from_envp)
1690 path = g_environ_getenv (envp, "PATH");
1691 if (search_path && path == NULL)
1692 path = g_getenv ("PATH");
1696 /* There is no 'PATH' in the environment. The default
1697 * search path in libc is the current directory followed by
1698 * the path 'confstr' returns for '_CS_PATH'.
1701 /* In GLib we put . last, for security, and don't use the
1702 * unportable confstr(); UNIX98 does not actually specify
1703 * what to search if PATH is unset. POSIX may, dunno.
1706 path = "/bin:/usr/bin:.";
1709 len = strlen (file) + 1;
1710 pathlen = strlen (path);
1711 freeme = name = g_malloc (pathlen + len + 1);
1713 /* Copy the file name at the top, including '\0' */
1714 memcpy (name + pathlen + 1, file, len);
1715 name = name + pathlen;
1716 /* And add the slash before the filename */
1725 p = my_strchrnul (path, ':');
1728 /* Two adjacent colons, or a colon at the beginning or the end
1729 * of 'PATH' means to search the current directory.
1733 startp = memcpy (name - (p - path), path, p - path);
1735 /* Try to execute this name. If it works, execv will not return. */
1737 execve (startp, argv, envp);
1739 execv (startp, argv);
1741 if (errno == ENOEXEC)
1742 script_execute (startp, argv, envp);
1747 /* Record the we got a 'Permission denied' error. If we end
1748 * up finding no executable we can use, we want to diagnose
1749 * that we did find one but were denied access.
1762 /* Those errors indicate the file is missing or not executable
1763 * by us, in which case we want to just try the next path
1770 /* Some strange filesystems like AFS return even
1771 * stranger error numbers. They cannot reasonably mean anything
1772 * else so ignore those, too.
1777 /* Some other error means we found an executable file, but
1778 * something went wrong executing it; return the error to our
1785 while (*p++ != '\0');
1787 /* We tried every element and none of them worked. */
1789 /* At least one failure was due to permissions, so report that
1797 /* Return the error from the last attempt (probably ENOENT). */
1802 * g_spawn_close_pid:
1803 * @pid: The process reference to close
1805 * On some platforms, notably Windows, the #GPid type represents a resource
1806 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1807 * is provided for this purpose. It should be used on all platforms, even
1808 * though it doesn't do anything under UNIX.
1811 g_spawn_close_pid (GPid pid)