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"
53 #include "gstrfuncs.h"
54 #include "gtestutils.h"
61 * @Short_description: process launching
62 * @Title: Spawning Processes
67 static gint g_execute (const gchar *file,
71 gboolean search_path_from_envp);
73 static gboolean make_pipe (gint p[2],
75 static gboolean fork_exec_with_pipes (gboolean intermediate_child,
76 const gchar *working_directory,
79 gboolean close_descriptors,
81 gboolean search_path_from_envp,
82 gboolean stdout_to_null,
83 gboolean stderr_to_null,
84 gboolean child_inherits_stdin,
85 gboolean file_and_argv_zero,
86 GSpawnChildSetupFunc child_setup,
90 gint *standard_output,
94 G_DEFINE_QUARK (g-exec-error-quark, g_spawn_error)
95 G_DEFINE_QUARK (g-spawn-exit-error-quark, g_spawn_exit_error)
99 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
100 * @argv: (array zero-terminated=1): child's argument vector
101 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
102 * @flags: flags from #GSpawnFlags
103 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
104 * @user_data: (closure): user data for @child_setup
105 * @child_pid: (out) (allow-none): return location for child process reference, or %NULL
106 * @error: return location for error
108 * See g_spawn_async_with_pipes() for a full description; this function
109 * simply calls the g_spawn_async_with_pipes() without any pipes.
111 * You should call g_spawn_close_pid() on the returned child process
112 * reference when you don't need it any more.
115 * If you are writing a GTK+ application, and the program you
116 * are spawning is a graphical application, too, then you may
117 * want to use gdk_spawn_on_screen() instead to ensure that
118 * the spawned program opens its windows on the right screen.
121 * <note><para> Note that the returned @child_pid on Windows is a
122 * handle to the child process and not its identifier. Process handles
123 * and process identifiers are different concepts on Windows.
126 * Return value: %TRUE on success, %FALSE if error is set
129 g_spawn_async (const gchar *working_directory,
133 GSpawnChildSetupFunc child_setup,
138 g_return_val_if_fail (argv != NULL, FALSE);
140 return g_spawn_async_with_pipes (working_directory,
150 /* Avoids a danger in threaded situations (calling close()
151 * on a file descriptor twice, and another thread has
152 * re-opened it since the first close)
155 close_and_invalidate (gint *fd)
161 (void) g_close (*fd, NULL);
166 /* Some versions of OS X define READ_OK in public headers */
171 READ_FAILED = 0, /* FALSE */
177 read_data (GString *str,
185 bytes = read (fd, buf, 4096);
191 g_string_append_len (str, buf, bytes);
194 else if (errno == EINTR)
203 _("Failed to read data from child process (%s)"),
216 on_sync_waitpid (GPid pid,
220 SyncWaitpidData *data = user_data;
221 *(data->status_p) = status;
222 g_main_loop_quit (data->loop);
227 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
228 * @argv: (array zero-terminated=1): child's argument vector
229 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
230 * @flags: flags from #GSpawnFlags
231 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
232 * @user_data: (closure): user data for @child_setup
233 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output, or %NULL
234 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child error messages, or %NULL
235 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid(), or %NULL
236 * @error: return location for error, or %NULL
238 * Executes a child synchronously (waits for the child to exit before returning).
239 * All output from the child is stored in @standard_output and @standard_error,
240 * if those parameters are non-%NULL. Note that you must set the
241 * %G_SPAWN_STDOUT_TO_DEV_NULL and %G_SPAWN_STDERR_TO_DEV_NULL flags when
242 * passing %NULL for @standard_output and @standard_error.
244 * If @exit_status is non-%NULL, the platform-specific exit status of
245 * the child is stored there; see the doucumentation of
246 * g_spawn_check_exit_status() for how to use and interpret this.
247 * Note that it is invalid to pass %G_SPAWN_DO_NOT_REAP_CHILD in
250 * If an error occurs, no data is returned in @standard_output,
251 * @standard_error, or @exit_status.
253 * This function calls g_spawn_async_with_pipes() internally; see that
254 * function for full details on the other parameters and details on
255 * how these functions work on Windows.
257 * Return value: %TRUE on success, %FALSE if an error was set.
260 g_spawn_sync (const gchar *working_directory,
264 GSpawnChildSetupFunc child_setup,
266 gchar **standard_output,
267 gchar **standard_error,
276 GString *outstr = NULL;
277 GString *errstr = NULL;
280 SyncWaitpidData waitpid_data;
282 g_return_val_if_fail (argv != NULL, FALSE);
283 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
284 g_return_val_if_fail (standard_output == NULL ||
285 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
286 g_return_val_if_fail (standard_error == NULL ||
287 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
289 /* Just to ensure segfaults if callers try to use
290 * these when an error is reported.
293 *standard_output = NULL;
296 *standard_error = NULL;
298 if (!fork_exec_with_pipes (FALSE,
302 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
303 (flags & G_SPAWN_SEARCH_PATH) != 0,
304 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
305 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
306 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
307 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
308 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
313 standard_output ? &outpipe : NULL,
314 standard_error ? &errpipe : NULL,
318 /* Read data from child. */
324 outstr = g_string_new (NULL);
329 errstr = g_string_new (NULL);
332 /* Read data until we get EOF on both pipes. */
341 FD_SET (outpipe, &fds);
343 FD_SET (errpipe, &fds);
345 ret = select (MAX (outpipe, errpipe) + 1,
348 NULL /* no timeout */);
362 _("Unexpected error in select() reading data from a child process (%s)"),
368 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
370 switch (read_data (outstr, outpipe, error))
376 close_and_invalidate (&outpipe);
387 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
389 switch (read_data (errstr, errpipe, error))
395 close_and_invalidate (&errpipe);
407 /* These should only be open still if we had an error. */
410 close_and_invalidate (&outpipe);
412 close_and_invalidate (&errpipe);
414 /* Now create a temporary main context and loop, with just one
415 * waitpid source. We used to invoke waitpid() directly here, but
416 * this way we unify with the worker thread in gmain.c.
419 GMainContext *context;
423 context = g_main_context_new ();
424 loop = g_main_loop_new (context, TRUE);
426 waitpid_data.loop = loop;
427 waitpid_data.status_p = &status;
429 source = g_child_watch_source_new (pid);
430 g_source_set_callback (source, (GSourceFunc)on_sync_waitpid, &waitpid_data, NULL);
431 g_source_attach (source, context);
432 g_source_unref (source);
434 g_main_loop_run (loop);
436 g_main_context_unref (context);
437 g_main_loop_unref (loop);
443 g_string_free (outstr, TRUE);
445 g_string_free (errstr, TRUE);
452 *exit_status = status;
455 *standard_output = g_string_free (outstr, FALSE);
458 *standard_error = g_string_free (errstr, FALSE);
465 * g_spawn_async_with_pipes:
466 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
467 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
468 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
469 * @flags: flags from #GSpawnFlags
470 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
471 * @user_data: (closure): user data for @child_setup
472 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
473 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
474 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
475 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
476 * @error: return location for error
478 * Executes a child program asynchronously (your program will not
479 * block waiting for the child to exit). The child program is
480 * specified by the only argument that must be provided, @argv. @argv
481 * should be a %NULL-terminated array of strings, to be passed as the
482 * argument vector for the child. The first string in @argv is of
483 * course the name of the program to execute. By default, the name of
484 * the program must be a full path. If @flags contains the
485 * %G_SPAWN_SEARCH_PATH flag, the <envar>PATH</envar> environment variable
486 * is used to search for the executable. If @flags contains the
487 * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the <envar>PATH</envar> variable from
488 * @envp is used to search for the executable.
489 * If both the %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP
490 * flags are set, the <envar>PATH</envar> variable from @envp takes precedence
491 * over the environment variable.
493 * If the program name is not a full path and %G_SPAWN_SEARCH_PATH flag is not
494 * used, then the program will be run from the current directory (or
495 * @working_directory, if specified); this might be unexpected or even
496 * dangerous in some cases when the current directory is world-writable.
498 * On Windows, note that all the string or string vector arguments to
499 * this function and the other g_spawn*() functions are in UTF-8, the
500 * GLib file name encoding. Unicode characters that are not part of
501 * the system codepage passed in these arguments will be correctly
502 * available in the spawned program only if it uses wide character API
503 * to retrieve its command line. For C programs built with Microsoft's
504 * tools it is enough to make the program have a wmain() instead of
505 * main(). wmain() has a wide character argument vector as parameter.
507 * At least currently, mingw doesn't support wmain(), so if you use
508 * mingw to develop the spawned program, it will have to call the
509 * undocumented function __wgetmainargs() to get the wide character
510 * argument vector and environment. See gspawn-win32-helper.c in the
511 * GLib sources or init.c in the mingw runtime sources for a prototype
512 * for that function. Alternatively, you can retrieve the Win32 system
513 * level wide character command line passed to the spawned program
514 * using the GetCommandLineW() function.
516 * On Windows the low-level child process creation API
517 * <function>CreateProcess()</function> doesn't use argument vectors,
518 * but a command line. The C runtime library's
519 * <function>spawn*()</function> family of functions (which
520 * g_spawn_async_with_pipes() eventually calls) paste the argument
521 * vector elements together into a command line, and the C runtime startup code
522 * does a corresponding reconstruction of an argument vector from the
523 * command line, to be passed to main(). Complications arise when you have
524 * argument vector elements that contain spaces of double quotes. The
525 * <function>spawn*()</function> functions don't do any quoting or
526 * escaping, but on the other hand the startup code does do unquoting
527 * and unescaping in order to enable receiving arguments with embedded
528 * spaces or double quotes. To work around this asymmetry,
529 * g_spawn_async_with_pipes() will do quoting and escaping on argument
530 * vector elements that need it before calling the C runtime
533 * The returned @child_pid on Windows is a handle to the child
534 * process, not its identifier. Process handles and process
535 * identifiers are different concepts on Windows.
537 * @envp is a %NULL-terminated array of strings, where each string
538 * has the form <literal>KEY=VALUE</literal>. This will become
539 * the child's environment. If @envp is %NULL, the child inherits its
540 * parent's environment.
542 * @flags should be the bitwise OR of any flags you want to affect the
543 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that the
544 * child will not automatically be reaped; you must use a child watch to
545 * be notified about the death of the child process. Eventually you must
546 * call g_spawn_close_pid() on the @child_pid, in order to free
547 * resources which may be associated with the child process. (On Unix,
548 * using a child watch is equivalent to calling waitpid() or handling
549 * the <literal>SIGCHLD</literal> signal manually. On Windows, calling g_spawn_close_pid()
550 * is equivalent to calling CloseHandle() on the process handle returned
551 * in @child_pid). See g_child_watch_add().
553 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
554 * descriptors will be inherited by the child; otherwise all
555 * descriptors except stdin/stdout/stderr will be closed before
556 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
557 * means that <literal>argv[0]</literal> need not be an absolute path, it
558 * will be looked for in the <envar>PATH</envar> environment variable.
559 * %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an absolute path, it
560 * will be looked for in the <envar>PATH</envar> variable from @envp. If
561 * both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP are used,
562 * the value from @envp takes precedence over the environment.
563 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
564 * be discarded, instead of going to the same location as the parent's
565 * standard output. If you use this flag, @standard_output must be %NULL.
566 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
567 * will be discarded, instead of going to the same location as the parent's
568 * standard error. If you use this flag, @standard_error must be %NULL.
569 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
570 * standard input (by default, the child's standard input is attached to
571 * /dev/null). If you use this flag, @standard_input must be %NULL.
572 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
573 * the file to execute, while the remaining elements are the
574 * actual argument vector to pass to the file. Normally
575 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
576 * passes all of @argv to the child.
578 * @child_setup and @user_data are a function and user data. On POSIX
579 * platforms, the function is called in the child after GLib has
580 * performed all the setup it plans to perform (including creating
581 * pipes, closing file descriptors, etc.) but before calling
582 * exec(). That is, @child_setup is called just
583 * before calling exec() in the child. Obviously
584 * actions taken in this function will only affect the child, not the
587 * On Windows, there is no separate fork() and exec()
588 * functionality. Child processes are created and run with a single
589 * API call, CreateProcess(). There is no sensible thing @child_setup
590 * could be used for on Windows so it is ignored and not called.
592 * If non-%NULL, @child_pid will on Unix be filled with the child's
593 * process ID. You can use the process ID to send signals to the
594 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
595 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
596 * filled with a handle to the child process only if you specified the
597 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
598 * process using the Win32 API, for example wait for its termination
599 * with the <function>WaitFor*()</function> functions, or examine its
600 * exit code with GetExitCodeProcess(). You should close the handle
601 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
603 * If non-%NULL, the @standard_input, @standard_output, @standard_error
604 * locations will be filled with file descriptors for writing to the child's
605 * standard input or reading from its standard output or standard error.
606 * The caller of g_spawn_async_with_pipes() must close these file descriptors
607 * when they are no longer in use. If these parameters are %NULL, the corresponding
608 * pipe won't be created.
610 * If @standard_input is NULL, the child's standard input is attached to
611 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
613 * If @standard_error is NULL, the child's standard error goes to the same
614 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
617 * If @standard_output is NULL, the child's standard output goes to the same
618 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
621 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
622 * If an error is set, the function returns %FALSE. Errors
623 * are reported even if they occur in the child (for example if the
624 * executable in <literal>argv[0]</literal> is not found). Typically
625 * the <literal>message</literal> field of returned errors should be displayed
626 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
628 * If an error occurs, @child_pid, @standard_input, @standard_output,
629 * and @standard_error will not be filled with valid values.
631 * If @child_pid is not %NULL and an error does not occur then the returned
632 * process reference must be closed using g_spawn_close_pid().
635 * If you are writing a GTK+ application, and the program you
636 * are spawning is a graphical application, too, then you may
637 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
638 * the spawned program opens its windows on the right screen.
641 * Return value: %TRUE on success, %FALSE if an error was set
644 g_spawn_async_with_pipes (const gchar *working_directory,
648 GSpawnChildSetupFunc child_setup,
651 gint *standard_input,
652 gint *standard_output,
653 gint *standard_error,
656 g_return_val_if_fail (argv != NULL, FALSE);
657 g_return_val_if_fail (standard_output == NULL ||
658 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
659 g_return_val_if_fail (standard_error == NULL ||
660 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
661 /* can't inherit stdin if we have an input pipe. */
662 g_return_val_if_fail (standard_input == NULL ||
663 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
665 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
669 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
670 (flags & G_SPAWN_SEARCH_PATH) != 0,
671 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
672 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
673 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
674 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
675 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
686 * g_spawn_command_line_sync:
687 * @command_line: a command line
688 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
689 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
690 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
691 * @error: return location for errors
693 * A simple version of g_spawn_sync() with little-used parameters
694 * removed, taking a command line instead of an argument vector. See
695 * g_spawn_sync() for full details. @command_line will be parsed by
696 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
697 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
698 * implications, so consider using g_spawn_sync() directly if
699 * appropriate. Possible errors are those from g_spawn_sync() and those
700 * from g_shell_parse_argv().
702 * If @exit_status is non-%NULL, the platform-specific exit status of
703 * the child is stored there; see the documentation of
704 * g_spawn_check_exit_status() for how to use and interpret this.
706 * On Windows, please note the implications of g_shell_parse_argv()
707 * parsing @command_line. Parsing is done according to Unix shell rules, not
708 * Windows command interpreter rules.
709 * Space is a separator, and backslashes are
710 * special. Thus you cannot simply pass a @command_line containing
711 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
712 * the backslashes will be eaten, and the space will act as a
713 * separator. You need to enclose such paths with single quotes, like
714 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
716 * Return value: %TRUE on success, %FALSE if an error was set
719 g_spawn_command_line_sync (const gchar *command_line,
720 gchar **standard_output,
721 gchar **standard_error,
728 g_return_val_if_fail (command_line != NULL, FALSE);
730 if (!g_shell_parse_argv (command_line,
735 retval = g_spawn_sync (NULL,
751 * g_spawn_command_line_async:
752 * @command_line: a command line
753 * @error: return location for errors
755 * A simple version of g_spawn_async() that parses a command line with
756 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
757 * command line in the background. Unlike g_spawn_async(), the
758 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
759 * that %G_SPAWN_SEARCH_PATH can have security implications, so
760 * consider using g_spawn_async() directly if appropriate. Possible
761 * errors are those from g_shell_parse_argv() and g_spawn_async().
763 * The same concerns on Windows apply as for g_spawn_command_line_sync().
765 * Return value: %TRUE on success, %FALSE if error is set.
768 g_spawn_command_line_async (const gchar *command_line,
774 g_return_val_if_fail (command_line != NULL, FALSE);
776 if (!g_shell_parse_argv (command_line,
781 retval = g_spawn_async (NULL,
795 * g_spawn_check_exit_status:
796 * @exit_status: An exit code as returned from g_spawn_sync()
799 * Set @error if @exit_status indicates the child exited abnormally
800 * (e.g. with a nonzero exit code, or via a fatal signal).
802 * The g_spawn_sync() and g_child_watch_add() family of APIs return an
803 * exit status for subprocesses encoded in a platform-specific way.
804 * On Unix, this is guaranteed to be in the same format
805 * <literal>waitpid(2)</literal> returns, and on Windows it is
806 * guaranteed to be the result of
807 * <literal>GetExitCodeProcess()</literal>. Prior to the introduction
808 * of this function in GLib 2.34, interpreting @exit_status required
809 * use of platform-specific APIs, which is problematic for software
810 * using GLib as a cross-platform layer.
812 * Additionally, many programs simply want to determine whether or not
813 * the child exited successfully, and either propagate a #GError or
814 * print a message to standard error. In that common case, this
815 * function can be used. Note that the error message in @error will
816 * contain human-readable information about the exit status.
818 * The <literal>domain</literal> and <literal>code</literal> of @error
819 * have special semantics in the case where the process has an "exit
820 * code", as opposed to being killed by a signal. On Unix, this
821 * happens if <literal>WIFEXITED</literal> would be true of
822 * @exit_status. On Windows, it is always the case.
824 * The special semantics are that the actual exit code will be the
825 * code set in @error, and the domain will be %G_SPAWN_EXIT_ERROR.
826 * This allows you to differentiate between different exit codes.
828 * If the process was terminated by some means other than an exit
829 * status, the domain will be %G_SPAWN_ERROR, and the code will be
830 * %G_SPAWN_ERROR_FAILED.
832 * This function just offers convenience; you can of course also check
833 * the available platform via a macro such as %G_OS_UNIX, and use
834 * <literal>WIFEXITED()</literal> and <literal>WEXITSTATUS()</literal>
835 * on @exit_status directly. Do not attempt to scan or parse the
836 * error message string; it may be translated and/or change in future
839 * Returns: %TRUE if child exited successfully, %FALSE otherwise (and @error will be set)
843 g_spawn_check_exit_status (gint exit_status,
846 gboolean ret = FALSE;
848 if (WIFEXITED (exit_status))
850 if (WEXITSTATUS (exit_status) != 0)
852 g_set_error (error, G_SPAWN_EXIT_ERROR, WEXITSTATUS (exit_status),
853 _("Child process exited with code %ld"),
854 (long) WEXITSTATUS (exit_status));
858 else if (WIFSIGNALED (exit_status))
860 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
861 _("Child process killed by signal %ld"),
862 (long) WTERMSIG (exit_status));
865 else if (WIFSTOPPED (exit_status))
867 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
868 _("Child process stopped by signal %ld"),
869 (long) WSTOPSIG (exit_status));
874 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
875 _("Child process exited abnormally"));
885 exec_err_to_g_error (gint en)
891 return G_SPAWN_ERROR_ACCES;
897 return G_SPAWN_ERROR_PERM;
903 return G_SPAWN_ERROR_TOO_BIG;
909 return G_SPAWN_ERROR_NOEXEC;
915 return G_SPAWN_ERROR_NAMETOOLONG;
921 return G_SPAWN_ERROR_NOENT;
927 return G_SPAWN_ERROR_NOMEM;
933 return G_SPAWN_ERROR_NOTDIR;
939 return G_SPAWN_ERROR_LOOP;
945 return G_SPAWN_ERROR_TXTBUSY;
951 return G_SPAWN_ERROR_IO;
957 return G_SPAWN_ERROR_NFILE;
963 return G_SPAWN_ERROR_MFILE;
969 return G_SPAWN_ERROR_INVAL;
975 return G_SPAWN_ERROR_ISDIR;
981 return G_SPAWN_ERROR_LIBBAD;
986 return G_SPAWN_ERROR_FAILED;
992 write_all (gint fd, gconstpointer vbuf, gsize to_write)
994 gchar *buf = (gchar *) vbuf;
998 gssize count = write (fd, buf, to_write);
1016 write_err_and_exit (gint fd, gint msg)
1020 write_all (fd, &msg, sizeof(msg));
1021 write_all (fd, &en, sizeof(en));
1027 set_cloexec (void *data, gint fd)
1029 if (fd >= GPOINTER_TO_INT (data))
1030 fcntl (fd, F_SETFD, FD_CLOEXEC);
1037 fdwalk (int (*cb)(void *data, int fd), void *data)
1043 #ifdef HAVE_SYS_RESOURCE_H
1050 if ((d = opendir("/proc/self/fd"))) {
1053 while ((de = readdir(d))) {
1057 if (de->d_name[0] == '.')
1061 l = strtol(de->d_name, &e, 10);
1062 if (errno != 0 || !e || *e)
1067 if ((glong) fd != l)
1073 if ((res = cb (data, fd)) != 0)
1081 /* If /proc is not mounted or not accessible we fall back to the old
1086 #ifdef HAVE_SYS_RESOURCE_H
1088 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
1089 open_max = rl.rlim_max;
1092 open_max = sysconf (_SC_OPEN_MAX);
1094 for (fd = 0; fd < open_max; fd++)
1095 if ((res = cb (data, fd)) != 0)
1103 sane_dup2 (gint fd1, gint fd2)
1108 ret = dup2 (fd1, fd2);
1109 if (ret < 0 && errno == EINTR)
1116 sane_open (const char *path, gint mode)
1121 ret = open (path, mode);
1122 if (ret < 0 && errno == EINTR)
1137 do_exec (gint child_err_report_fd,
1141 const gchar *working_directory,
1144 gboolean close_descriptors,
1145 gboolean search_path,
1146 gboolean search_path_from_envp,
1147 gboolean stdout_to_null,
1148 gboolean stderr_to_null,
1149 gboolean child_inherits_stdin,
1150 gboolean file_and_argv_zero,
1151 GSpawnChildSetupFunc child_setup,
1154 if (working_directory && chdir (working_directory) < 0)
1155 write_err_and_exit (child_err_report_fd,
1156 CHILD_CHDIR_FAILED);
1158 /* Close all file descriptors but stdin stdout and stderr as
1159 * soon as we exec. Note that this includes
1160 * child_err_report_fd, which keeps the parent from blocking
1161 * forever on the other end of that pipe.
1163 if (close_descriptors)
1165 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1169 /* We need to do child_err_report_fd anyway */
1170 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1173 /* Redirect pipes as required */
1177 /* dup2 can't actually fail here I don't think */
1179 if (sane_dup2 (stdin_fd, 0) < 0)
1180 write_err_and_exit (child_err_report_fd,
1183 /* ignore this if it doesn't work */
1184 close_and_invalidate (&stdin_fd);
1186 else if (!child_inherits_stdin)
1188 /* Keep process from blocking on a read of stdin */
1189 gint read_null = open ("/dev/null", O_RDONLY);
1190 g_assert (read_null != -1);
1191 sane_dup2 (read_null, 0);
1192 close_and_invalidate (&read_null);
1197 /* dup2 can't actually fail here I don't think */
1199 if (sane_dup2 (stdout_fd, 1) < 0)
1200 write_err_and_exit (child_err_report_fd,
1203 /* ignore this if it doesn't work */
1204 close_and_invalidate (&stdout_fd);
1206 else if (stdout_to_null)
1208 gint write_null = sane_open ("/dev/null", O_WRONLY);
1209 g_assert (write_null != -1);
1210 sane_dup2 (write_null, 1);
1211 close_and_invalidate (&write_null);
1216 /* dup2 can't actually fail here I don't think */
1218 if (sane_dup2 (stderr_fd, 2) < 0)
1219 write_err_and_exit (child_err_report_fd,
1222 /* ignore this if it doesn't work */
1223 close_and_invalidate (&stderr_fd);
1225 else if (stderr_to_null)
1227 gint write_null = sane_open ("/dev/null", O_WRONLY);
1228 sane_dup2 (write_null, 2);
1229 close_and_invalidate (&write_null);
1232 /* Call user function just before we exec */
1235 (* child_setup) (user_data);
1239 file_and_argv_zero ? argv + 1 : argv,
1240 envp, search_path, search_path_from_envp);
1243 write_err_and_exit (child_err_report_fd,
1260 if (bytes >= sizeof(gint)*2)
1261 break; /* give up, who knows what happened, should not be
1267 ((gchar*)buf) + bytes,
1268 sizeof(gint) * n_ints_in_buf - bytes);
1269 if (chunk < 0 && errno == EINTR)
1276 /* Some weird shit happened, bail out */
1279 G_SPAWN_ERROR_FAILED,
1280 _("Failed to read from child pipe (%s)"),
1281 g_strerror (errsv));
1285 else if (chunk == 0)
1287 else /* chunk > 0 */
1291 *n_ints_read = (gint)(bytes / sizeof(gint));
1297 fork_exec_with_pipes (gboolean intermediate_child,
1298 const gchar *working_directory,
1301 gboolean close_descriptors,
1302 gboolean search_path,
1303 gboolean search_path_from_envp,
1304 gboolean stdout_to_null,
1305 gboolean stderr_to_null,
1306 gboolean child_inherits_stdin,
1307 gboolean file_and_argv_zero,
1308 GSpawnChildSetupFunc child_setup,
1311 gint *standard_input,
1312 gint *standard_output,
1313 gint *standard_error,
1317 gint stdin_pipe[2] = { -1, -1 };
1318 gint stdout_pipe[2] = { -1, -1 };
1319 gint stderr_pipe[2] = { -1, -1 };
1320 gint child_err_report_pipe[2] = { -1, -1 };
1321 gint child_pid_report_pipe[2] = { -1, -1 };
1324 if (!make_pipe (child_err_report_pipe, error))
1327 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1328 goto cleanup_and_fail;
1330 if (standard_input && !make_pipe (stdin_pipe, error))
1331 goto cleanup_and_fail;
1333 if (standard_output && !make_pipe (stdout_pipe, error))
1334 goto cleanup_and_fail;
1336 if (standard_error && !make_pipe (stderr_pipe, error))
1337 goto cleanup_and_fail;
1348 _("Failed to fork (%s)"),
1349 g_strerror (errsv));
1351 goto cleanup_and_fail;
1355 /* Immediate child. This may or may not be the child that
1356 * actually execs the new process.
1359 /* Reset some signal handlers that we may use */
1360 signal (SIGCHLD, SIG_DFL);
1361 signal (SIGINT, SIG_DFL);
1362 signal (SIGTERM, SIG_DFL);
1363 signal (SIGHUP, SIG_DFL);
1365 /* Be sure we crash if the parent exits
1366 * and we write to the err_report_pipe
1368 signal (SIGPIPE, SIG_DFL);
1370 /* Close the parent's end of the pipes;
1371 * not needed in the close_descriptors case,
1374 close_and_invalidate (&child_err_report_pipe[0]);
1375 close_and_invalidate (&child_pid_report_pipe[0]);
1376 close_and_invalidate (&stdin_pipe[1]);
1377 close_and_invalidate (&stdout_pipe[0]);
1378 close_and_invalidate (&stderr_pipe[0]);
1380 if (intermediate_child)
1382 /* We need to fork an intermediate child that launches the
1383 * final child. The purpose of the intermediate child
1384 * is to exit, so we can waitpid() it immediately.
1385 * Then the grandchild will not become a zombie.
1387 GPid grandchild_pid;
1389 grandchild_pid = fork ();
1391 if (grandchild_pid < 0)
1393 /* report -1 as child PID */
1394 write_all (child_pid_report_pipe[1], &grandchild_pid,
1395 sizeof(grandchild_pid));
1397 write_err_and_exit (child_err_report_pipe[1],
1400 else if (grandchild_pid == 0)
1402 do_exec (child_err_report_pipe[1],
1411 search_path_from_envp,
1414 child_inherits_stdin,
1421 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1422 close_and_invalidate (&child_pid_report_pipe[1]);
1429 /* Just run the child.
1432 do_exec (child_err_report_pipe[1],
1441 search_path_from_envp,
1444 child_inherits_stdin,
1457 /* Close the uncared-about ends of the pipes */
1458 close_and_invalidate (&child_err_report_pipe[1]);
1459 close_and_invalidate (&child_pid_report_pipe[1]);
1460 close_and_invalidate (&stdin_pipe[0]);
1461 close_and_invalidate (&stdout_pipe[1]);
1462 close_and_invalidate (&stderr_pipe[1]);
1464 /* If we had an intermediate child, reap it */
1465 if (intermediate_child)
1468 if (waitpid (pid, &status, 0) < 0)
1472 else if (errno == ECHILD)
1473 ; /* do nothing, child already reaped */
1475 g_warning ("waitpid() should not fail in "
1476 "'fork_exec_with_pipes'");
1481 if (!read_ints (child_err_report_pipe[0],
1484 goto cleanup_and_fail;
1488 /* Error from the child. */
1492 case CHILD_CHDIR_FAILED:
1495 G_SPAWN_ERROR_CHDIR,
1496 _("Failed to change to directory '%s' (%s)"),
1498 g_strerror (buf[1]));
1502 case CHILD_EXEC_FAILED:
1505 exec_err_to_g_error (buf[1]),
1506 _("Failed to execute child process \"%s\" (%s)"),
1508 g_strerror (buf[1]));
1512 case CHILD_DUP2_FAILED:
1515 G_SPAWN_ERROR_FAILED,
1516 _("Failed to redirect output or input of child process (%s)"),
1517 g_strerror (buf[1]));
1521 case CHILD_FORK_FAILED:
1525 _("Failed to fork child process (%s)"),
1526 g_strerror (buf[1]));
1532 G_SPAWN_ERROR_FAILED,
1533 _("Unknown error executing child process \"%s\""),
1538 goto cleanup_and_fail;
1541 /* Get child pid from intermediate child pipe. */
1542 if (intermediate_child)
1546 if (!read_ints (child_pid_report_pipe[0],
1547 buf, 1, &n_ints, error))
1548 goto cleanup_and_fail;
1556 G_SPAWN_ERROR_FAILED,
1557 _("Failed to read enough data from child pid pipe (%s)"),
1558 g_strerror (errsv));
1559 goto cleanup_and_fail;
1563 /* we have the child pid */
1568 /* Success against all odds! return the information */
1569 close_and_invalidate (&child_err_report_pipe[0]);
1570 close_and_invalidate (&child_pid_report_pipe[0]);
1576 *standard_input = stdin_pipe[1];
1577 if (standard_output)
1578 *standard_output = stdout_pipe[0];
1580 *standard_error = stderr_pipe[0];
1587 /* There was an error from the Child, reap the child to avoid it being
1594 if (waitpid (pid, NULL, 0) < 0)
1598 else if (errno == ECHILD)
1599 ; /* do nothing, child already reaped */
1601 g_warning ("waitpid() should not fail in "
1602 "'fork_exec_with_pipes'");
1606 close_and_invalidate (&child_err_report_pipe[0]);
1607 close_and_invalidate (&child_err_report_pipe[1]);
1608 close_and_invalidate (&child_pid_report_pipe[0]);
1609 close_and_invalidate (&child_pid_report_pipe[1]);
1610 close_and_invalidate (&stdin_pipe[0]);
1611 close_and_invalidate (&stdin_pipe[1]);
1612 close_and_invalidate (&stdout_pipe[0]);
1613 close_and_invalidate (&stdout_pipe[1]);
1614 close_and_invalidate (&stderr_pipe[0]);
1615 close_and_invalidate (&stderr_pipe[1]);
1621 make_pipe (gint p[2],
1629 G_SPAWN_ERROR_FAILED,
1630 _("Failed to create pipe for communicating with child process (%s)"),
1631 g_strerror (errsv));
1638 /* Based on execvp from GNU C Library */
1641 script_execute (const gchar *file,
1645 /* Count the arguments. */
1650 /* Construct an argument list for the shell. */
1654 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1656 new_argv[0] = (char *) "/bin/sh";
1657 new_argv[1] = (char *) file;
1660 new_argv[argc + 1] = argv[argc];
1664 /* Execute the shell. */
1666 execve (new_argv[0], new_argv, envp);
1668 execv (new_argv[0], new_argv);
1675 my_strchrnul (const gchar *str, gchar c)
1677 gchar *p = (gchar*) str;
1678 while (*p && (*p != c))
1685 g_execute (const gchar *file,
1688 gboolean search_path,
1689 gboolean search_path_from_envp)
1693 /* We check the simple case first. */
1698 if (!(search_path || search_path_from_envp) || strchr (file, '/') != NULL)
1700 /* Don't search when it contains a slash. */
1702 execve (file, argv, envp);
1706 if (errno == ENOEXEC)
1707 script_execute (file, argv, envp);
1711 gboolean got_eacces = 0;
1712 const gchar *path, *p;
1713 gchar *name, *freeme;
1718 if (search_path_from_envp)
1719 path = g_environ_getenv (envp, "PATH");
1720 if (search_path && path == NULL)
1721 path = g_getenv ("PATH");
1725 /* There is no `PATH' in the environment. The default
1726 * search path in libc is the current directory followed by
1727 * the path `confstr' returns for `_CS_PATH'.
1730 /* In GLib we put . last, for security, and don't use the
1731 * unportable confstr(); UNIX98 does not actually specify
1732 * what to search if PATH is unset. POSIX may, dunno.
1735 path = "/bin:/usr/bin:.";
1738 len = strlen (file) + 1;
1739 pathlen = strlen (path);
1740 freeme = name = g_malloc (pathlen + len + 1);
1742 /* Copy the file name at the top, including '\0' */
1743 memcpy (name + pathlen + 1, file, len);
1744 name = name + pathlen;
1745 /* And add the slash before the filename */
1754 p = my_strchrnul (path, ':');
1757 /* Two adjacent colons, or a colon at the beginning or the end
1758 * of `PATH' means to search the current directory.
1762 startp = memcpy (name - (p - path), path, p - path);
1764 /* Try to execute this name. If it works, execv will not return. */
1766 execve (startp, argv, envp);
1768 execv (startp, argv);
1770 if (errno == ENOEXEC)
1771 script_execute (startp, argv, envp);
1776 /* Record the we got a `Permission denied' error. If we end
1777 * up finding no executable we can use, we want to diagnose
1778 * that we did find one but were denied access.
1791 /* Those errors indicate the file is missing or not executable
1792 * by us, in which case we want to just try the next path
1799 /* Some strange filesystems like AFS return even
1800 * stranger error numbers. They cannot reasonably mean anything
1801 * else so ignore those, too.
1806 /* Some other error means we found an executable file, but
1807 * something went wrong executing it; return the error to our
1814 while (*p++ != '\0');
1816 /* We tried every element and none of them worked. */
1818 /* At least one failure was due to permissions, so report that
1826 /* Return the error from the last attempt (probably ENOENT). */
1831 * g_spawn_close_pid:
1832 * @pid: The process reference to close
1834 * On some platforms, notably Windows, the #GPid type represents a resource
1835 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1836 * is provided for this purpose. It should be used on all platforms, even
1837 * though it doesn't do anything under UNIX.
1840 g_spawn_close_pid (GPid pid)