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 */
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.
113 * If you are writing a GTK+ application, and the program you
114 * are spawning is a graphical application, too, then you may
115 * want to use gdk_spawn_on_screen() instead to ensure that
116 * the spawned program opens its windows on the right screen.
119 * <note><para> Note that the returned @child_pid on Windows is a
120 * handle to the child process and not its identifier. Process handles
121 * and process identifiers are different concepts on Windows.
124 * Return value: %TRUE on success, %FALSE if error is set
127 g_spawn_async (const gchar *working_directory,
131 GSpawnChildSetupFunc child_setup,
136 g_return_val_if_fail (argv != NULL, FALSE);
138 return g_spawn_async_with_pipes (working_directory,
148 /* Avoids a danger in threaded situations (calling close()
149 * on a file descriptor twice, and another thread has
150 * re-opened it since the first close)
153 close_and_invalidate (gint *fd)
163 if (ret == -1 && errno == EINTR)
171 /* Some versions of OS X define READ_OK in public headers */
176 READ_FAILED = 0, /* FALSE */
182 read_data (GString *str,
190 bytes = read (fd, buf, 4096);
196 g_string_append_len (str, buf, bytes);
199 else if (errno == EINTR)
208 _("Failed to read data from child process (%s)"),
221 on_sync_waitpid (GPid pid,
225 SyncWaitpidData *data = user_data;
226 *(data->status_p) = status;
227 g_main_loop_quit (data->loop);
232 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
233 * @argv: (array zero-terminated=1): child's argument vector
234 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
235 * @flags: flags from #GSpawnFlags
236 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
237 * @user_data: (closure): user data for @child_setup
238 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output, or %NULL
239 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child error messages, or %NULL
240 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid(), or %NULL
241 * @error: return location for error, or %NULL
243 * Executes a child synchronously (waits for the child to exit before returning).
244 * All output from the child is stored in @standard_output and @standard_error,
245 * if those parameters are non-%NULL. Note that you must set the
246 * %G_SPAWN_STDOUT_TO_DEV_NULL and %G_SPAWN_STDERR_TO_DEV_NULL flags when
247 * passing %NULL for @standard_output and @standard_error.
249 * If @exit_status is non-%NULL, the platform-specific exit status of
250 * the child is stored there; see the doucumentation of
251 * g_spawn_check_exit_status() for how to use and interpret this.
252 * Note that it is invalid to pass %G_SPAWN_DO_NOT_REAP_CHILD in
255 * If an error occurs, no data is returned in @standard_output,
256 * @standard_error, or @exit_status.
258 * This function calls g_spawn_async_with_pipes() internally; see that
259 * function for full details on the other parameters and details on
260 * how these functions work on Windows.
262 * Return value: %TRUE on success, %FALSE if an error was set.
265 g_spawn_sync (const gchar *working_directory,
269 GSpawnChildSetupFunc child_setup,
271 gchar **standard_output,
272 gchar **standard_error,
281 GString *outstr = NULL;
282 GString *errstr = NULL;
285 SyncWaitpidData waitpid_data;
287 g_return_val_if_fail (argv != NULL, FALSE);
288 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
289 g_return_val_if_fail (standard_output == NULL ||
290 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
291 g_return_val_if_fail (standard_error == NULL ||
292 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
294 /* Just to ensure segfaults if callers try to use
295 * these when an error is reported.
298 *standard_output = NULL;
301 *standard_error = NULL;
303 if (!fork_exec_with_pipes (FALSE,
307 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
308 (flags & G_SPAWN_SEARCH_PATH) != 0,
309 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
310 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
311 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
312 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
313 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
314 (flags & G_SPAWN_CLOEXEC_PIPES) != 0,
319 standard_output ? &outpipe : NULL,
320 standard_error ? &errpipe : NULL,
324 /* Read data from child. */
330 outstr = g_string_new (NULL);
335 errstr = g_string_new (NULL);
338 /* Read data until we get EOF on both pipes. */
347 FD_SET (outpipe, &fds);
349 FD_SET (errpipe, &fds);
351 ret = select (MAX (outpipe, errpipe) + 1,
354 NULL /* no timeout */);
368 _("Unexpected error in select() reading data from a child process (%s)"),
374 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
376 switch (read_data (outstr, outpipe, error))
382 close_and_invalidate (&outpipe);
393 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
395 switch (read_data (errstr, errpipe, error))
401 close_and_invalidate (&errpipe);
413 /* These should only be open still if we had an error. */
416 close_and_invalidate (&outpipe);
418 close_and_invalidate (&errpipe);
420 /* Now create a temporary main context and loop, with just one
421 * waitpid source. We used to invoke waitpid() directly here, but
422 * this way we unify with the worker thread in gmain.c.
425 GMainContext *context;
429 context = g_main_context_new ();
430 loop = g_main_loop_new (context, TRUE);
432 waitpid_data.loop = loop;
433 waitpid_data.status_p = &status;
435 source = g_child_watch_source_new (pid);
436 g_source_set_callback (source, (GSourceFunc)on_sync_waitpid, &waitpid_data, NULL);
437 g_source_attach (source, context);
438 g_source_unref (source);
440 g_main_loop_run (loop);
442 g_main_context_unref (context);
443 g_main_loop_unref (loop);
449 g_string_free (outstr, TRUE);
451 g_string_free (errstr, TRUE);
458 *exit_status = status;
461 *standard_output = g_string_free (outstr, FALSE);
464 *standard_error = g_string_free (errstr, FALSE);
471 * g_spawn_async_with_pipes:
472 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
473 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
474 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
475 * @flags: flags from #GSpawnFlags
476 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
477 * @user_data: (closure): user data for @child_setup
478 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
479 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
480 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
481 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
482 * @error: return location for error
484 * Executes a child program asynchronously (your program will not
485 * block waiting for the child to exit). The child program is
486 * specified by the only argument that must be provided, @argv. @argv
487 * should be a %NULL-terminated array of strings, to be passed as the
488 * argument vector for the child. The first string in @argv is of
489 * course the name of the program to execute. By default, the name of
490 * the program must be a full path. If @flags contains the
491 * %G_SPAWN_SEARCH_PATH flag, the <envar>PATH</envar> environment variable
492 * is used to search for the executable. If @flags contains the
493 * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the <envar>PATH</envar> variable from
494 * @envp is used to search for the executable.
495 * If both the %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP
496 * flags are set, the <envar>PATH</envar> variable from @envp takes precedence
497 * over the environment variable.
499 * If the program name is not a full path and %G_SPAWN_SEARCH_PATH flag is not
500 * used, then the program will be run from the current directory (or
501 * @working_directory, if specified); this might be unexpected or even
502 * dangerous in some cases when the current directory is world-writable.
504 * On Windows, note that all the string or string vector arguments to
505 * this function and the other g_spawn*() functions are in UTF-8, the
506 * GLib file name encoding. Unicode characters that are not part of
507 * the system codepage passed in these arguments will be correctly
508 * available in the spawned program only if it uses wide character API
509 * to retrieve its command line. For C programs built with Microsoft's
510 * tools it is enough to make the program have a wmain() instead of
511 * main(). wmain() has a wide character argument vector as parameter.
513 * At least currently, mingw doesn't support wmain(), so if you use
514 * mingw to develop the spawned program, it will have to call the
515 * undocumented function __wgetmainargs() to get the wide character
516 * argument vector and environment. See gspawn-win32-helper.c in the
517 * GLib sources or init.c in the mingw runtime sources for a prototype
518 * for that function. Alternatively, you can retrieve the Win32 system
519 * level wide character command line passed to the spawned program
520 * using the GetCommandLineW() function.
522 * On Windows the low-level child process creation API
523 * <function>CreateProcess()</function> doesn't use argument vectors,
524 * but a command line. The C runtime library's
525 * <function>spawn*()</function> family of functions (which
526 * g_spawn_async_with_pipes() eventually calls) paste the argument
527 * vector elements together into a command line, and the C runtime startup code
528 * does a corresponding reconstruction of an argument vector from the
529 * command line, to be passed to main(). Complications arise when you have
530 * argument vector elements that contain spaces of double quotes. The
531 * <function>spawn*()</function> functions don't do any quoting or
532 * escaping, but on the other hand the startup code does do unquoting
533 * and unescaping in order to enable receiving arguments with embedded
534 * spaces or double quotes. To work around this asymmetry,
535 * g_spawn_async_with_pipes() will do quoting and escaping on argument
536 * vector elements that need it before calling the C runtime
539 * The returned @child_pid on Windows is a handle to the child
540 * process, not its identifier. Process handles and process
541 * identifiers are different concepts on Windows.
543 * @envp is a %NULL-terminated array of strings, where each string
544 * has the form <literal>KEY=VALUE</literal>. This will become
545 * the child's environment. If @envp is %NULL, the child inherits its
546 * parent's environment.
548 * @flags should be the bitwise OR of any flags you want to affect the
549 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that the
550 * child will not automatically be reaped; you must use a child watch to
551 * be notified about the death of the child process. Eventually you must
552 * call g_spawn_close_pid() on the @child_pid, in order to free
553 * resources which may be associated with the child process. (On Unix,
554 * using a child watch is equivalent to calling waitpid() or handling
555 * the <literal>SIGCHLD</literal> signal manually. On Windows, calling g_spawn_close_pid()
556 * is equivalent to calling CloseHandle() on the process handle returned
557 * in @child_pid). See g_child_watch_add().
559 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
560 * descriptors will be inherited by the child; otherwise all
561 * descriptors except stdin/stdout/stderr will be closed before
562 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
563 * means that <literal>argv[0]</literal> need not be an absolute path, it
564 * will be looked for in the <envar>PATH</envar> environment variable.
565 * %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an absolute path, it
566 * will be looked for in the <envar>PATH</envar> variable from @envp. If
567 * both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP are used,
568 * the value from @envp takes precedence over the environment.
569 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
570 * be discarded, instead of going to the same location as the parent's
571 * standard output. If you use this flag, @standard_output must be %NULL.
572 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
573 * will be discarded, instead of going to the same location as the parent's
574 * standard error. If you use this flag, @standard_error must be %NULL.
575 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
576 * standard input (by default, the child's standard input is attached to
577 * /dev/null). If you use this flag, @standard_input must be %NULL.
578 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
579 * the file to execute, while the remaining elements are the
580 * actual argument vector to pass to the file. Normally
581 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
582 * passes all of @argv to the child.
584 * @child_setup and @user_data are a function and user data. On POSIX
585 * platforms, the function is called in the child after GLib has
586 * performed all the setup it plans to perform (including creating
587 * pipes, closing file descriptors, etc.) but before calling
588 * exec(). That is, @child_setup is called just
589 * before calling exec() in the child. Obviously
590 * actions taken in this function will only affect the child, not the
593 * On Windows, there is no separate fork() and exec()
594 * functionality. Child processes are created and run with a single
595 * API call, CreateProcess(). There is no sensible thing @child_setup
596 * could be used for on Windows so it is ignored and not called.
598 * If non-%NULL, @child_pid will on Unix be filled with the child's
599 * process ID. You can use the process ID to send signals to the
600 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
601 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
602 * filled with a handle to the child process only if you specified the
603 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
604 * process using the Win32 API, for example wait for its termination
605 * with the <function>WaitFor*()</function> functions, or examine its
606 * exit code with GetExitCodeProcess(). You should close the handle
607 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
609 * If non-%NULL, the @standard_input, @standard_output, @standard_error
610 * locations will be filled with file descriptors for writing to the child's
611 * standard input or reading from its standard output or standard error.
612 * The caller of g_spawn_async_with_pipes() must close these file descriptors
613 * when they are no longer in use. If these parameters are %NULL, the corresponding
614 * pipe won't be created.
616 * If @standard_input is NULL, the child's standard input is attached to
617 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
619 * If @standard_error is NULL, the child's standard error goes to the same
620 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
623 * If @standard_output is NULL, the child's standard output goes to the same
624 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
627 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
628 * If an error is set, the function returns %FALSE. Errors
629 * are reported even if they occur in the child (for example if the
630 * executable in <literal>argv[0]</literal> is not found). Typically
631 * the <literal>message</literal> field of returned errors should be displayed
632 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
634 * If an error occurs, @child_pid, @standard_input, @standard_output,
635 * and @standard_error will not be filled with valid values.
637 * If @child_pid is not %NULL and an error does not occur then the returned
638 * process reference must be closed using g_spawn_close_pid().
641 * If you are writing a GTK+ application, and the program you
642 * are spawning is a graphical application, too, then you may
643 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
644 * the spawned program opens its windows on the right screen.
647 * Return value: %TRUE on success, %FALSE if an error was set
650 g_spawn_async_with_pipes (const gchar *working_directory,
654 GSpawnChildSetupFunc child_setup,
657 gint *standard_input,
658 gint *standard_output,
659 gint *standard_error,
662 g_return_val_if_fail (argv != NULL, FALSE);
663 g_return_val_if_fail (standard_output == NULL ||
664 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
665 g_return_val_if_fail (standard_error == NULL ||
666 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
667 /* can't inherit stdin if we have an input pipe. */
668 g_return_val_if_fail (standard_input == NULL ||
669 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
671 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
675 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
676 (flags & G_SPAWN_SEARCH_PATH) != 0,
677 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
678 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
679 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
680 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
681 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
682 (flags & G_SPAWN_CLOEXEC_PIPES) != 0,
693 * g_spawn_command_line_sync:
694 * @command_line: a command line
695 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
696 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
697 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
698 * @error: return location for errors
700 * A simple version of g_spawn_sync() with little-used parameters
701 * removed, taking a command line instead of an argument vector. See
702 * g_spawn_sync() for full details. @command_line will be parsed by
703 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
704 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
705 * implications, so consider using g_spawn_sync() directly if
706 * appropriate. Possible errors are those from g_spawn_sync() and those
707 * from g_shell_parse_argv().
709 * If @exit_status is non-%NULL, the platform-specific exit status of
710 * the child is stored there; see the documentation of
711 * g_spawn_check_exit_status() for how to use and interpret this.
713 * On Windows, please note the implications of g_shell_parse_argv()
714 * parsing @command_line. Parsing is done according to Unix shell rules, not
715 * Windows command interpreter rules.
716 * Space is a separator, and backslashes are
717 * special. Thus you cannot simply pass a @command_line containing
718 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
719 * the backslashes will be eaten, and the space will act as a
720 * separator. You need to enclose such paths with single quotes, like
721 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
723 * Return value: %TRUE on success, %FALSE if an error was set
726 g_spawn_command_line_sync (const gchar *command_line,
727 gchar **standard_output,
728 gchar **standard_error,
735 g_return_val_if_fail (command_line != NULL, FALSE);
737 if (!g_shell_parse_argv (command_line,
742 retval = g_spawn_sync (NULL,
758 * g_spawn_command_line_async:
759 * @command_line: a command line
760 * @error: return location for errors
762 * A simple version of g_spawn_async() that parses a command line with
763 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
764 * command line in the background. Unlike g_spawn_async(), the
765 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
766 * that %G_SPAWN_SEARCH_PATH can have security implications, so
767 * consider using g_spawn_async() directly if appropriate. Possible
768 * errors are those from g_shell_parse_argv() and g_spawn_async().
770 * The same concerns on Windows apply as for g_spawn_command_line_sync().
772 * Return value: %TRUE on success, %FALSE if error is set.
775 g_spawn_command_line_async (const gchar *command_line,
781 g_return_val_if_fail (command_line != NULL, FALSE);
783 if (!g_shell_parse_argv (command_line,
788 retval = g_spawn_async (NULL,
802 * g_spawn_check_exit_status:
803 * @exit_status: An exit code as returned from g_spawn_sync()
806 * Set @error if @exit_status indicates the child exited abnormally
807 * (e.g. with a nonzero exit code, or via a fatal signal).
809 * The g_spawn_sync() and g_child_watch_add() family of APIs return an
810 * exit status for subprocesses encoded in a platform-specific way.
811 * On Unix, this is guaranteed to be in the same format
812 * <literal>waitpid(2)</literal> returns, and on Windows it is
813 * guaranteed to be the result of
814 * <literal>GetExitCodeProcess()</literal>. Prior to the introduction
815 * of this function in GLib 2.34, interpreting @exit_status required
816 * use of platform-specific APIs, which is problematic for software
817 * using GLib as a cross-platform layer.
819 * Additionally, many programs simply want to determine whether or not
820 * the child exited successfully, and either propagate a #GError or
821 * print a message to standard error. In that common case, this
822 * function can be used. Note that the error message in @error will
823 * contain human-readable information about the exit status.
825 * The <literal>domain</literal> and <literal>code</literal> of @error
826 * have special semantics in the case where the process has an "exit
827 * code", as opposed to being killed by a signal. On Unix, this
828 * happens if <literal>WIFEXITED</literal> would be true of
829 * @exit_status. On Windows, it is always the case.
831 * The special semantics are that the actual exit code will be the
832 * code set in @error, and the domain will be %G_SPAWN_EXIT_ERROR.
833 * This allows you to differentiate between different exit codes.
835 * If the process was terminated by some means other than an exit
836 * status, the domain will be %G_SPAWN_ERROR, and the code will be
837 * %G_SPAWN_ERROR_FAILED.
839 * This function just offers convenience; you can of course also check
840 * the available platform via a macro such as %G_OS_UNIX, and use
841 * <literal>WIFEXITED()</literal> and <literal>WEXITSTATUS()</literal>
842 * on @exit_status directly. Do not attempt to scan or parse the
843 * error message string; it may be translated and/or change in future
846 * Returns: %TRUE if child exited successfully, %FALSE otherwise (and @error will be set)
850 g_spawn_check_exit_status (gint exit_status,
853 gboolean ret = FALSE;
855 if (WIFEXITED (exit_status))
857 if (WEXITSTATUS (exit_status) != 0)
859 g_set_error (error, G_SPAWN_EXIT_ERROR, WEXITSTATUS (exit_status),
860 _("Child process exited with code %ld"),
861 (long) WEXITSTATUS (exit_status));
865 else if (WIFSIGNALED (exit_status))
867 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
868 _("Child process killed by signal %ld"),
869 (long) WTERMSIG (exit_status));
872 else if (WIFSTOPPED (exit_status))
874 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
875 _("Child process stopped by signal %ld"),
876 (long) WSTOPSIG (exit_status));
881 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
882 _("Child process exited abnormally"));
892 exec_err_to_g_error (gint en)
898 return G_SPAWN_ERROR_ACCES;
904 return G_SPAWN_ERROR_PERM;
910 return G_SPAWN_ERROR_TOO_BIG;
916 return G_SPAWN_ERROR_NOEXEC;
922 return G_SPAWN_ERROR_NAMETOOLONG;
928 return G_SPAWN_ERROR_NOENT;
934 return G_SPAWN_ERROR_NOMEM;
940 return G_SPAWN_ERROR_NOTDIR;
946 return G_SPAWN_ERROR_LOOP;
952 return G_SPAWN_ERROR_TXTBUSY;
958 return G_SPAWN_ERROR_IO;
964 return G_SPAWN_ERROR_NFILE;
970 return G_SPAWN_ERROR_MFILE;
976 return G_SPAWN_ERROR_INVAL;
982 return G_SPAWN_ERROR_ISDIR;
988 return G_SPAWN_ERROR_LIBBAD;
993 return G_SPAWN_ERROR_FAILED;
999 write_all (gint fd, gconstpointer vbuf, gsize to_write)
1001 gchar *buf = (gchar *) vbuf;
1003 while (to_write > 0)
1005 gssize count = write (fd, buf, to_write);
1023 write_err_and_exit (gint fd, gint msg)
1027 write_all (fd, &msg, sizeof(msg));
1028 write_all (fd, &en, sizeof(en));
1034 set_cloexec (void *data, gint fd)
1036 if (fd >= GPOINTER_TO_INT (data))
1037 fcntl (fd, F_SETFD, FD_CLOEXEC);
1044 fdwalk (int (*cb)(void *data, int fd), void *data)
1050 #ifdef HAVE_SYS_RESOURCE_H
1057 if ((d = opendir("/proc/self/fd"))) {
1060 while ((de = readdir(d))) {
1064 if (de->d_name[0] == '.')
1068 l = strtol(de->d_name, &e, 10);
1069 if (errno != 0 || !e || *e)
1074 if ((glong) fd != l)
1080 if ((res = cb (data, fd)) != 0)
1088 /* If /proc is not mounted or not accessible we fall back to the old
1093 #ifdef HAVE_SYS_RESOURCE_H
1095 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
1096 open_max = rl.rlim_max;
1099 open_max = sysconf (_SC_OPEN_MAX);
1101 for (fd = 0; fd < open_max; fd++)
1102 if ((res = cb (data, fd)) != 0)
1110 sane_dup2 (gint fd1, gint fd2)
1115 ret = dup2 (fd1, fd2);
1116 if (ret < 0 && errno == EINTR)
1123 sane_open (const char *path, gint mode)
1128 ret = open (path, mode);
1129 if (ret < 0 && errno == EINTR)
1144 do_exec (gint child_err_report_fd,
1148 const gchar *working_directory,
1151 gboolean close_descriptors,
1152 gboolean search_path,
1153 gboolean search_path_from_envp,
1154 gboolean stdout_to_null,
1155 gboolean stderr_to_null,
1156 gboolean child_inherits_stdin,
1157 gboolean file_and_argv_zero,
1158 GSpawnChildSetupFunc child_setup,
1161 if (working_directory && chdir (working_directory) < 0)
1162 write_err_and_exit (child_err_report_fd,
1163 CHILD_CHDIR_FAILED);
1165 /* Close all file descriptors but stdin stdout and stderr as
1166 * soon as we exec. Note that this includes
1167 * child_err_report_fd, which keeps the parent from blocking
1168 * forever on the other end of that pipe.
1170 if (close_descriptors)
1172 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1176 /* We need to do child_err_report_fd anyway */
1177 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1180 /* Redirect pipes as required */
1184 /* dup2 can't actually fail here I don't think */
1186 if (sane_dup2 (stdin_fd, 0) < 0)
1187 write_err_and_exit (child_err_report_fd,
1190 /* ignore this if it doesn't work */
1191 close_and_invalidate (&stdin_fd);
1193 else if (!child_inherits_stdin)
1195 /* Keep process from blocking on a read of stdin */
1196 gint read_null = open ("/dev/null", O_RDONLY);
1197 g_assert (read_null != -1);
1198 sane_dup2 (read_null, 0);
1199 close_and_invalidate (&read_null);
1204 /* dup2 can't actually fail here I don't think */
1206 if (sane_dup2 (stdout_fd, 1) < 0)
1207 write_err_and_exit (child_err_report_fd,
1210 /* ignore this if it doesn't work */
1211 close_and_invalidate (&stdout_fd);
1213 else if (stdout_to_null)
1215 gint write_null = sane_open ("/dev/null", O_WRONLY);
1216 g_assert (write_null != -1);
1217 sane_dup2 (write_null, 1);
1218 close_and_invalidate (&write_null);
1223 /* dup2 can't actually fail here I don't think */
1225 if (sane_dup2 (stderr_fd, 2) < 0)
1226 write_err_and_exit (child_err_report_fd,
1229 /* ignore this if it doesn't work */
1230 close_and_invalidate (&stderr_fd);
1232 else if (stderr_to_null)
1234 gint write_null = sane_open ("/dev/null", O_WRONLY);
1235 sane_dup2 (write_null, 2);
1236 close_and_invalidate (&write_null);
1239 /* Call user function just before we exec */
1242 (* child_setup) (user_data);
1246 file_and_argv_zero ? argv + 1 : argv,
1247 envp, search_path, search_path_from_envp);
1250 write_err_and_exit (child_err_report_fd,
1267 if (bytes >= sizeof(gint)*2)
1268 break; /* give up, who knows what happened, should not be
1274 ((gchar*)buf) + bytes,
1275 sizeof(gint) * n_ints_in_buf - bytes);
1276 if (chunk < 0 && errno == EINTR)
1283 /* Some weird shit happened, bail out */
1286 G_SPAWN_ERROR_FAILED,
1287 _("Failed to read from child pipe (%s)"),
1288 g_strerror (errsv));
1292 else if (chunk == 0)
1294 else /* chunk > 0 */
1298 *n_ints_read = (gint)(bytes / sizeof(gint));
1304 fork_exec_with_pipes (gboolean intermediate_child,
1305 const gchar *working_directory,
1308 gboolean close_descriptors,
1309 gboolean search_path,
1310 gboolean search_path_from_envp,
1311 gboolean stdout_to_null,
1312 gboolean stderr_to_null,
1313 gboolean child_inherits_stdin,
1314 gboolean file_and_argv_zero,
1315 gboolean cloexec_pipes,
1316 GSpawnChildSetupFunc child_setup,
1319 gint *standard_input,
1320 gint *standard_output,
1321 gint *standard_error,
1325 gint stdin_pipe[2] = { -1, -1 };
1326 gint stdout_pipe[2] = { -1, -1 };
1327 gint stderr_pipe[2] = { -1, -1 };
1328 gint child_err_report_pipe[2] = { -1, -1 };
1329 gint child_pid_report_pipe[2] = { -1, -1 };
1330 guint pipe_flags = cloexec_pipes ? FD_CLOEXEC : 0;
1333 if (!g_unix_open_pipe (child_err_report_pipe, pipe_flags, error))
1336 if (intermediate_child && !g_unix_open_pipe (child_pid_report_pipe, pipe_flags, error))
1337 goto cleanup_and_fail;
1339 if (standard_input && !g_unix_open_pipe (stdin_pipe, pipe_flags, error))
1340 goto cleanup_and_fail;
1342 if (standard_output && !g_unix_open_pipe (stdout_pipe, pipe_flags, error))
1343 goto cleanup_and_fail;
1345 if (standard_error && !g_unix_open_pipe (stderr_pipe, FD_CLOEXEC, error))
1346 goto cleanup_and_fail;
1357 _("Failed to fork (%s)"),
1358 g_strerror (errsv));
1360 goto cleanup_and_fail;
1364 /* Immediate child. This may or may not be the child that
1365 * actually execs the new process.
1368 /* Reset some signal handlers that we may use */
1369 signal (SIGCHLD, SIG_DFL);
1370 signal (SIGINT, SIG_DFL);
1371 signal (SIGTERM, SIG_DFL);
1372 signal (SIGHUP, SIG_DFL);
1374 /* Be sure we crash if the parent exits
1375 * and we write to the err_report_pipe
1377 signal (SIGPIPE, SIG_DFL);
1379 /* Close the parent's end of the pipes;
1380 * not needed in the close_descriptors case,
1383 close_and_invalidate (&child_err_report_pipe[0]);
1384 close_and_invalidate (&child_pid_report_pipe[0]);
1385 close_and_invalidate (&stdin_pipe[1]);
1386 close_and_invalidate (&stdout_pipe[0]);
1387 close_and_invalidate (&stderr_pipe[0]);
1389 if (intermediate_child)
1391 /* We need to fork an intermediate child that launches the
1392 * final child. The purpose of the intermediate child
1393 * is to exit, so we can waitpid() it immediately.
1394 * Then the grandchild will not become a zombie.
1396 GPid grandchild_pid;
1398 grandchild_pid = fork ();
1400 if (grandchild_pid < 0)
1402 /* report -1 as child PID */
1403 write_all (child_pid_report_pipe[1], &grandchild_pid,
1404 sizeof(grandchild_pid));
1406 write_err_and_exit (child_err_report_pipe[1],
1409 else if (grandchild_pid == 0)
1411 do_exec (child_err_report_pipe[1],
1420 search_path_from_envp,
1423 child_inherits_stdin,
1430 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1431 close_and_invalidate (&child_pid_report_pipe[1]);
1438 /* Just run the child.
1441 do_exec (child_err_report_pipe[1],
1450 search_path_from_envp,
1453 child_inherits_stdin,
1466 /* Close the uncared-about ends of the pipes */
1467 close_and_invalidate (&child_err_report_pipe[1]);
1468 close_and_invalidate (&child_pid_report_pipe[1]);
1469 close_and_invalidate (&stdin_pipe[0]);
1470 close_and_invalidate (&stdout_pipe[1]);
1471 close_and_invalidate (&stderr_pipe[1]);
1473 /* If we had an intermediate child, reap it */
1474 if (intermediate_child)
1477 if (waitpid (pid, &status, 0) < 0)
1481 else if (errno == ECHILD)
1482 ; /* do nothing, child already reaped */
1484 g_warning ("waitpid() should not fail in "
1485 "'fork_exec_with_pipes'");
1490 if (!read_ints (child_err_report_pipe[0],
1493 goto cleanup_and_fail;
1497 /* Error from the child. */
1501 case CHILD_CHDIR_FAILED:
1504 G_SPAWN_ERROR_CHDIR,
1505 _("Failed to change to directory '%s' (%s)"),
1507 g_strerror (buf[1]));
1511 case CHILD_EXEC_FAILED:
1514 exec_err_to_g_error (buf[1]),
1515 _("Failed to execute child process \"%s\" (%s)"),
1517 g_strerror (buf[1]));
1521 case CHILD_DUP2_FAILED:
1524 G_SPAWN_ERROR_FAILED,
1525 _("Failed to redirect output or input of child process (%s)"),
1526 g_strerror (buf[1]));
1530 case CHILD_FORK_FAILED:
1534 _("Failed to fork child process (%s)"),
1535 g_strerror (buf[1]));
1541 G_SPAWN_ERROR_FAILED,
1542 _("Unknown error executing child process \"%s\""),
1547 goto cleanup_and_fail;
1550 /* Get child pid from intermediate child pipe. */
1551 if (intermediate_child)
1555 if (!read_ints (child_pid_report_pipe[0],
1556 buf, 1, &n_ints, error))
1557 goto cleanup_and_fail;
1565 G_SPAWN_ERROR_FAILED,
1566 _("Failed to read enough data from child pid pipe (%s)"),
1567 g_strerror (errsv));
1568 goto cleanup_and_fail;
1572 /* we have the child pid */
1577 /* Success against all odds! return the information */
1578 close_and_invalidate (&child_err_report_pipe[0]);
1579 close_and_invalidate (&child_pid_report_pipe[0]);
1585 *standard_input = stdin_pipe[1];
1586 if (standard_output)
1587 *standard_output = stdout_pipe[0];
1589 *standard_error = stderr_pipe[0];
1596 /* There was an error from the Child, reap the child to avoid it being
1603 if (waitpid (pid, NULL, 0) < 0)
1607 else if (errno == ECHILD)
1608 ; /* do nothing, child already reaped */
1610 g_warning ("waitpid() should not fail in "
1611 "'fork_exec_with_pipes'");
1615 close_and_invalidate (&child_err_report_pipe[0]);
1616 close_and_invalidate (&child_err_report_pipe[1]);
1617 close_and_invalidate (&child_pid_report_pipe[0]);
1618 close_and_invalidate (&child_pid_report_pipe[1]);
1619 close_and_invalidate (&stdin_pipe[0]);
1620 close_and_invalidate (&stdin_pipe[1]);
1621 close_and_invalidate (&stdout_pipe[0]);
1622 close_and_invalidate (&stdout_pipe[1]);
1623 close_and_invalidate (&stderr_pipe[0]);
1624 close_and_invalidate (&stderr_pipe[1]);
1629 /* Based on execvp from GNU C Library */
1632 script_execute (const gchar *file,
1636 /* Count the arguments. */
1641 /* Construct an argument list for the shell. */
1645 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1647 new_argv[0] = (char *) "/bin/sh";
1648 new_argv[1] = (char *) file;
1651 new_argv[argc + 1] = argv[argc];
1655 /* Execute the shell. */
1657 execve (new_argv[0], new_argv, envp);
1659 execv (new_argv[0], new_argv);
1666 my_strchrnul (const gchar *str, gchar c)
1668 gchar *p = (gchar*) str;
1669 while (*p && (*p != c))
1676 g_execute (const gchar *file,
1679 gboolean search_path,
1680 gboolean search_path_from_envp)
1684 /* We check the simple case first. */
1689 if (!(search_path || search_path_from_envp) || strchr (file, '/') != NULL)
1691 /* Don't search when it contains a slash. */
1693 execve (file, argv, envp);
1697 if (errno == ENOEXEC)
1698 script_execute (file, argv, envp);
1702 gboolean got_eacces = 0;
1703 const gchar *path, *p;
1704 gchar *name, *freeme;
1709 if (search_path_from_envp)
1710 path = g_environ_getenv (envp, "PATH");
1711 if (search_path && path == NULL)
1712 path = g_getenv ("PATH");
1716 /* There is no `PATH' in the environment. The default
1717 * search path in libc is the current directory followed by
1718 * the path `confstr' returns for `_CS_PATH'.
1721 /* In GLib we put . last, for security, and don't use the
1722 * unportable confstr(); UNIX98 does not actually specify
1723 * what to search if PATH is unset. POSIX may, dunno.
1726 path = "/bin:/usr/bin:.";
1729 len = strlen (file) + 1;
1730 pathlen = strlen (path);
1731 freeme = name = g_malloc (pathlen + len + 1);
1733 /* Copy the file name at the top, including '\0' */
1734 memcpy (name + pathlen + 1, file, len);
1735 name = name + pathlen;
1736 /* And add the slash before the filename */
1745 p = my_strchrnul (path, ':');
1748 /* Two adjacent colons, or a colon at the beginning or the end
1749 * of `PATH' means to search the current directory.
1753 startp = memcpy (name - (p - path), path, p - path);
1755 /* Try to execute this name. If it works, execv will not return. */
1757 execve (startp, argv, envp);
1759 execv (startp, argv);
1761 if (errno == ENOEXEC)
1762 script_execute (startp, argv, envp);
1767 /* Record the we got a `Permission denied' error. If we end
1768 * up finding no executable we can use, we want to diagnose
1769 * that we did find one but were denied access.
1782 /* Those errors indicate the file is missing or not executable
1783 * by us, in which case we want to just try the next path
1790 /* Some strange filesystems like AFS return even
1791 * stranger error numbers. They cannot reasonably mean anything
1792 * else so ignore those, too.
1797 /* Some other error means we found an executable file, but
1798 * something went wrong executing it; return the error to our
1805 while (*p++ != '\0');
1807 /* We tried every element and none of them worked. */
1809 /* At least one failure was due to permissions, so report that
1817 /* Return the error from the last attempt (probably ENOENT). */
1822 * g_spawn_close_pid:
1823 * @pid: The process reference to close
1825 * On some platforms, notably Windows, the #GPid type represents a resource
1826 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1827 * is provided for this purpose. It should be used on all platforms, even
1828 * though it doesn't do anything under UNIX.
1831 g_spawn_close_pid (GPid pid)