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 */
50 #include "gstrfuncs.h"
51 #include "gtestutils.h"
58 * @Short_description: process launching
59 * @Title: Spawning Processes
64 static gint g_execute (const gchar *file,
68 gboolean search_path_from_envp);
70 static gboolean make_pipe (gint p[2],
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 GSpawnChildSetupFunc child_setup,
87 gint *standard_output,
92 g_spawn_error_quark (void)
94 return g_quark_from_static_string ("g-exec-error-quark");
98 g_spawn_exit_error_quark (void)
100 return g_quark_from_static_string ("g-spawn-exit-error-quark");
105 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
106 * @argv: (array zero-terminated=1): child's argument vector
107 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
108 * @flags: flags from #GSpawnFlags
109 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
110 * @user_data: (closure): user data for @child_setup
111 * @child_pid: (out) (allow-none): return location for child process reference, or %NULL
112 * @error: return location for error
114 * See g_spawn_async_with_pipes() for a full description; this function
115 * simply calls the g_spawn_async_with_pipes() without any pipes.
117 * You should call g_spawn_close_pid() on the returned child process
118 * reference when you don't need it any more.
121 * If you are writing a GTK+ application, and the program you
122 * are spawning is a graphical application, too, then you may
123 * want to use gdk_spawn_on_screen() instead to ensure that
124 * the spawned program opens its windows on the right screen.
127 * <note><para> Note that the returned @child_pid on Windows is a
128 * handle to the child process and not its identifier. Process handles
129 * and process identifiers are different concepts on Windows.
132 * Return value: %TRUE on success, %FALSE if error is set
135 g_spawn_async (const gchar *working_directory,
139 GSpawnChildSetupFunc child_setup,
144 g_return_val_if_fail (argv != NULL, FALSE);
146 return g_spawn_async_with_pipes (working_directory,
156 /* Avoids a danger in threaded situations (calling close()
157 * on a file descriptor twice, and another thread has
158 * re-opened it since the first close)
161 close_and_invalidate (gint *fd)
171 if (ret == -1 && errno == EINTR)
179 /* Some versions of OS X define READ_OK in public headers */
184 READ_FAILED = 0, /* FALSE */
190 read_data (GString *str,
198 bytes = read (fd, buf, 4096);
204 g_string_append_len (str, buf, bytes);
207 else if (errno == EINTR)
216 _("Failed to read data from child process (%s)"),
225 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
226 * @argv: (array zero-terminated=1): child's argument vector
227 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
228 * @flags: flags from #GSpawnFlags
229 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
230 * @user_data: (closure): user data for @child_setup
231 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output, or %NULL
232 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child error messages, or %NULL
233 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid(), or %NULL
234 * @error: return location for error, or %NULL
236 * Executes a child synchronously (waits for the child to exit before returning).
237 * All output from the child is stored in @standard_output and @standard_error,
238 * if those parameters are non-%NULL. Note that you must set the
239 * %G_SPAWN_STDOUT_TO_DEV_NULL and %G_SPAWN_STDERR_TO_DEV_NULL flags when
240 * passing %NULL for @standard_output and @standard_error.
242 * If @exit_status is non-%NULL, the platform-specific exit status of
243 * the child is stored there; see the doucumentation of
244 * g_spawn_check_exit_status() for how to use and interpret this.
245 * Note that it is invalid to pass %G_SPAWN_DO_NOT_REAP_CHILD in
248 * If an error occurs, no data is returned in @standard_output,
249 * @standard_error, or @exit_status.
251 * This function calls g_spawn_async_with_pipes() internally; see that
252 * function for full details on the other parameters and details on
253 * how these functions work on Windows.
255 * Return value: %TRUE on success, %FALSE if an error was set.
258 g_spawn_sync (const gchar *working_directory,
262 GSpawnChildSetupFunc child_setup,
264 gchar **standard_output,
265 gchar **standard_error,
274 GString *outstr = NULL;
275 GString *errstr = NULL;
279 g_return_val_if_fail (argv != NULL, FALSE);
280 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
281 g_return_val_if_fail (standard_output == NULL ||
282 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
283 g_return_val_if_fail (standard_error == NULL ||
284 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
286 /* Just to ensure segfaults if callers try to use
287 * these when an error is reported.
290 *standard_output = NULL;
293 *standard_error = NULL;
295 if (!fork_exec_with_pipes (FALSE,
299 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
300 (flags & G_SPAWN_SEARCH_PATH) != 0,
301 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
302 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
303 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
304 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
305 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
310 standard_output ? &outpipe : NULL,
311 standard_error ? &errpipe : NULL,
315 /* Read data from child. */
321 outstr = g_string_new (NULL);
326 errstr = g_string_new (NULL);
329 /* Read data until we get EOF on both pipes. */
338 FD_SET (outpipe, &fds);
340 FD_SET (errpipe, &fds);
342 ret = select (MAX (outpipe, errpipe) + 1,
345 NULL /* no timeout */);
359 _("Unexpected error in select() reading data from a child process (%s)"),
365 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
367 switch (read_data (outstr, outpipe, error))
373 close_and_invalidate (&outpipe);
384 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
386 switch (read_data (errstr, errpipe, error))
392 close_and_invalidate (&errpipe);
404 /* These should only be open still if we had an error. */
407 close_and_invalidate (&outpipe);
409 close_and_invalidate (&errpipe);
411 /* Wait for child to exit, even if we have
416 ret = waitpid (pid, &status, 0);
422 else if (errno == ECHILD)
426 g_warning ("In call to g_spawn_sync(), exit status of a child process was requested but SIGCHLD action was set to SIG_IGN and ECHILD was received by waitpid(), so exit status can't be returned. This is a bug in the program calling g_spawn_sync(); either don't request the exit status, or don't set the SIGCHLD action.");
430 /* We don't need the exit status. */
435 if (!failed) /* avoid error pileups */
444 _("Unexpected error in waitpid() (%s)"),
453 g_string_free (outstr, TRUE);
455 g_string_free (errstr, TRUE);
462 *exit_status = status;
465 *standard_output = g_string_free (outstr, FALSE);
468 *standard_error = g_string_free (errstr, FALSE);
475 * g_spawn_async_with_pipes:
476 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
477 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
478 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
479 * @flags: flags from #GSpawnFlags
480 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
481 * @user_data: (closure): user data for @child_setup
482 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
483 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
484 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
485 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
486 * @error: return location for error
488 * Executes a child program asynchronously (your program will not
489 * block waiting for the child to exit). The child program is
490 * specified by the only argument that must be provided, @argv. @argv
491 * should be a %NULL-terminated array of strings, to be passed as the
492 * argument vector for the child. The first string in @argv is of
493 * course the name of the program to execute. By default, the name of
494 * the program must be a full path. If @flags contains the
495 * %G_SPAWN_SEARCH_PATH flag, the <envar>PATH</envar> environment variable
496 * is used to search for the executable. If @flags contains the
497 * %G_SPAWN_SEARCH_PATH_FROM_ENVP flag, the <envar>PATH</envar> variable from
498 * @envp is used to search for the executable.
499 * If both the %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP
500 * flags are set, the <envar>PATH</envar> variable from @envp takes precedence
501 * over the environment variable.
503 * If the program name is not a full path and %G_SPAWN_SEARCH_PATH flag is not
504 * used, then the program will be run from the current directory (or
505 * @working_directory, if specified); this might be unexpected or even
506 * dangerous in some cases when the current directory is world-writable.
508 * On Windows, note that all the string or string vector arguments to
509 * this function and the other g_spawn*() functions are in UTF-8, the
510 * GLib file name encoding. Unicode characters that are not part of
511 * the system codepage passed in these arguments will be correctly
512 * available in the spawned program only if it uses wide character API
513 * to retrieve its command line. For C programs built with Microsoft's
514 * tools it is enough to make the program have a wmain() instead of
515 * main(). wmain() has a wide character argument vector as parameter.
517 * At least currently, mingw doesn't support wmain(), so if you use
518 * mingw to develop the spawned program, it will have to call the
519 * undocumented function __wgetmainargs() to get the wide character
520 * argument vector and environment. See gspawn-win32-helper.c in the
521 * GLib sources or init.c in the mingw runtime sources for a prototype
522 * for that function. Alternatively, you can retrieve the Win32 system
523 * level wide character command line passed to the spawned program
524 * using the GetCommandLineW() function.
526 * On Windows the low-level child process creation API
527 * <function>CreateProcess()</function> doesn't use argument vectors,
528 * but a command line. The C runtime library's
529 * <function>spawn*()</function> family of functions (which
530 * g_spawn_async_with_pipes() eventually calls) paste the argument
531 * vector elements together into a command line, and the C runtime startup code
532 * does a corresponding reconstruction of an argument vector from the
533 * command line, to be passed to main(). Complications arise when you have
534 * argument vector elements that contain spaces of double quotes. The
535 * <function>spawn*()</function> functions don't do any quoting or
536 * escaping, but on the other hand the startup code does do unquoting
537 * and unescaping in order to enable receiving arguments with embedded
538 * spaces or double quotes. To work around this asymmetry,
539 * g_spawn_async_with_pipes() will do quoting and escaping on argument
540 * vector elements that need it before calling the C runtime
543 * The returned @child_pid on Windows is a handle to the child
544 * process, not its identifier. Process handles and process
545 * identifiers are different concepts on Windows.
547 * @envp is a %NULL-terminated array of strings, where each string
548 * has the form <literal>KEY=VALUE</literal>. This will become
549 * the child's environment. If @envp is %NULL, the child inherits its
550 * parent's environment.
552 * @flags should be the bitwise OR of any flags you want to affect the
553 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that the
554 * child will not automatically be reaped; you must use a child watch to
555 * be notified about the death of the child process. Eventually you must
556 * call g_spawn_close_pid() on the @child_pid, in order to free
557 * resources which may be associated with the child process. (On Unix,
558 * using a child watch is equivalent to calling waitpid() or handling
559 * the <literal>SIGCHLD</literal> signal manually. On Windows, calling g_spawn_close_pid()
560 * is equivalent to calling CloseHandle() on the process handle returned
561 * in @child_pid). See g_child_watch_add().
563 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
564 * descriptors will be inherited by the child; otherwise all
565 * descriptors except stdin/stdout/stderr will be closed before
566 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
567 * means that <literal>argv[0]</literal> need not be an absolute path, it
568 * will be looked for in the <envar>PATH</envar> environment variable.
569 * %G_SPAWN_SEARCH_PATH_FROM_ENVP means need not be an absolute path, it
570 * will be looked for in the <envar>PATH</envar> variable from @envp. If
571 * both %G_SPAWN_SEARCH_PATH and %G_SPAWN_SEARCH_PATH_FROM_ENVP are used,
572 * the value from @envp takes precedence over the environment.
573 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
574 * be discarded, instead of going to the same location as the parent's
575 * standard output. If you use this flag, @standard_output must be %NULL.
576 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
577 * will be discarded, instead of going to the same location as the parent's
578 * standard error. If you use this flag, @standard_error must be %NULL.
579 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
580 * standard input (by default, the child's standard input is attached to
581 * /dev/null). If you use this flag, @standard_input must be %NULL.
582 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
583 * the file to execute, while the remaining elements are the
584 * actual argument vector to pass to the file. Normally
585 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
586 * passes all of @argv to the child.
588 * @child_setup and @user_data are a function and user data. On POSIX
589 * platforms, the function is called in the child after GLib has
590 * performed all the setup it plans to perform (including creating
591 * pipes, closing file descriptors, etc.) but before calling
592 * exec(). That is, @child_setup is called just
593 * before calling exec() in the child. Obviously
594 * actions taken in this function will only affect the child, not the
597 * On Windows, there is no separate fork() and exec()
598 * functionality. Child processes are created and run with a single
599 * API call, CreateProcess(). There is no sensible thing @child_setup
600 * could be used for on Windows so it is ignored and not called.
602 * If non-%NULL, @child_pid will on Unix be filled with the child's
603 * process ID. You can use the process ID to send signals to the
604 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
605 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
606 * filled with a handle to the child process only if you specified the
607 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
608 * process using the Win32 API, for example wait for its termination
609 * with the <function>WaitFor*()</function> functions, or examine its
610 * exit code with GetExitCodeProcess(). You should close the handle
611 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
613 * If non-%NULL, the @standard_input, @standard_output, @standard_error
614 * locations will be filled with file descriptors for writing to the child's
615 * standard input or reading from its standard output or standard error.
616 * The caller of g_spawn_async_with_pipes() must close these file descriptors
617 * when they are no longer in use. If these parameters are %NULL, the corresponding
618 * pipe won't be created.
620 * If @standard_input is NULL, the child's standard input is attached to
621 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
623 * If @standard_error is NULL, the child's standard error goes to the same
624 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
627 * If @standard_output is NULL, the child's standard output goes to the same
628 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
631 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
632 * If an error is set, the function returns %FALSE. Errors
633 * are reported even if they occur in the child (for example if the
634 * executable in <literal>argv[0]</literal> is not found). Typically
635 * the <literal>message</literal> field of returned errors should be displayed
636 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
638 * If an error occurs, @child_pid, @standard_input, @standard_output,
639 * and @standard_error will not be filled with valid values.
641 * If @child_pid is not %NULL and an error does not occur then the returned
642 * process reference must be closed using g_spawn_close_pid().
645 * If you are writing a GTK+ application, and the program you
646 * are spawning is a graphical application, too, then you may
647 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
648 * the spawned program opens its windows on the right screen.
651 * Return value: %TRUE on success, %FALSE if an error was set
654 g_spawn_async_with_pipes (const gchar *working_directory,
658 GSpawnChildSetupFunc child_setup,
661 gint *standard_input,
662 gint *standard_output,
663 gint *standard_error,
666 g_return_val_if_fail (argv != NULL, FALSE);
667 g_return_val_if_fail (standard_output == NULL ||
668 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
669 g_return_val_if_fail (standard_error == NULL ||
670 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
671 /* can't inherit stdin if we have an input pipe. */
672 g_return_val_if_fail (standard_input == NULL ||
673 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
675 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
679 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
680 (flags & G_SPAWN_SEARCH_PATH) != 0,
681 (flags & G_SPAWN_SEARCH_PATH_FROM_ENVP) != 0,
682 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
683 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
684 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
685 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
696 * g_spawn_command_line_sync:
697 * @command_line: a command line
698 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
699 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
700 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
701 * @error: return location for errors
703 * A simple version of g_spawn_sync() with little-used parameters
704 * removed, taking a command line instead of an argument vector. See
705 * g_spawn_sync() for full details. @command_line will be parsed by
706 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
707 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
708 * implications, so consider using g_spawn_sync() directly if
709 * appropriate. Possible errors are those from g_spawn_sync() and those
710 * from g_shell_parse_argv().
712 * If @exit_status is non-%NULL, the platform-specific exit status of
713 * the child is stored there; see the documentation of
714 * g_spawn_check_exit_status() for how to use and interpret this.
716 * On Windows, please note the implications of g_shell_parse_argv()
717 * parsing @command_line. Parsing is done according to Unix shell rules, not
718 * Windows command interpreter rules.
719 * Space is a separator, and backslashes are
720 * special. Thus you cannot simply pass a @command_line containing
721 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
722 * the backslashes will be eaten, and the space will act as a
723 * separator. You need to enclose such paths with single quotes, like
724 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
726 * Return value: %TRUE on success, %FALSE if an error was set
729 g_spawn_command_line_sync (const gchar *command_line,
730 gchar **standard_output,
731 gchar **standard_error,
738 g_return_val_if_fail (command_line != NULL, FALSE);
740 if (!g_shell_parse_argv (command_line,
745 retval = g_spawn_sync (NULL,
761 * g_spawn_command_line_async:
762 * @command_line: a command line
763 * @error: return location for errors
765 * A simple version of g_spawn_async() that parses a command line with
766 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
767 * command line in the background. Unlike g_spawn_async(), the
768 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
769 * that %G_SPAWN_SEARCH_PATH can have security implications, so
770 * consider using g_spawn_async() directly if appropriate. Possible
771 * errors are those from g_shell_parse_argv() and g_spawn_async().
773 * The same concerns on Windows apply as for g_spawn_command_line_sync().
775 * Return value: %TRUE on success, %FALSE if error is set.
778 g_spawn_command_line_async (const gchar *command_line,
784 g_return_val_if_fail (command_line != NULL, FALSE);
786 if (!g_shell_parse_argv (command_line,
791 retval = g_spawn_async (NULL,
805 * g_spawn_check_exit_status:
806 * @exit_status: An exit code as returned from g_spawn_sync()
809 * Set @error if @exit_status indicates the child exited abnormally
810 * (e.g. with a nonzero exit code, or via a fatal signal).
812 * The g_spawn_sync() and g_child_watch_add() family of APIs return an
813 * exit status for subprocesses encoded in a platform-specific way.
814 * On Unix, this is guaranteed to be in the same format
815 * <literal>waitpid(2)</literal> returns, and on Windows it is
816 * guaranteed to be the result of
817 * <literal>GetExitCodeProcess()</literal>. Prior to the introduction
818 * of this function in GLib 2.34, interpreting @exit_status required
819 * use of platform-specific APIs, which is problematic for software
820 * using GLib as a cross-platform layer.
822 * Additionally, many programs simply want to determine whether or not
823 * the child exited successfully, and either propagate a #GError or
824 * print a message to standard error. In that common case, this
825 * function can be used. Note that the error message in @error will
826 * contain human-readable information about the exit status.
828 * The <literal>domain</literal> and <literal>code</literal> of @error
829 * have special semantics in the case where the process has an "exit
830 * code", as opposed to being killed by a signal. On Unix, this
831 * happens if <literal>WIFEXITED</literal> would be true of
832 * @exit_status. On Windows, it is always the case.
834 * The special semantics are that the actual exit code will be the
835 * code set in @error, and the domain will be %G_SPAWN_EXIT_ERROR.
836 * This allows you to differentiate between different exit codes.
838 * If the process was terminated by some means other than an exit
839 * status, the domain will be %G_SPAWN_ERROR, and the code will be
840 * %G_SPAWN_ERROR_FAILED.
842 * This function just offers convenience; you can of course also check
843 * the available platform via a macro such as %G_OS_UNIX, and use
844 * <literal>WIFEXITED()</literal> and <literal>WEXITSTATUS()</literal>
845 * on @exit_status directly. Do not attempt to scan or parse the
846 * error message string; it may be translated and/or change in future
849 * Returns: %TRUE if child exited successfully, %FALSE otherwise (and @error will be set)
853 g_spawn_check_exit_status (gint exit_status,
856 gboolean ret = FALSE;
859 if (WIFEXITED (exit_status))
861 if (WEXITSTATUS (exit_status) != 0)
863 g_set_error (error, G_SPAWN_EXIT_ERROR, WEXITSTATUS (exit_status),
864 _("Child process exited with code %ld"),
865 (long) WEXITSTATUS (exit_status));
869 else if (WIFSIGNALED (exit_status))
871 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
872 _("Child process killed by signal %ld"),
873 (long) WTERMSIG (exit_status));
876 else if (WIFSTOPPED (exit_status))
878 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
879 _("Child process stopped by signal %ld"),
880 (long) WSTOPSIG (exit_status));
885 g_set_error (error, G_SPAWN_ERROR, G_SPAWN_ERROR_FAILED,
886 _("Child process exited abnormally"));
890 if (exit_status != 0)
892 g_set_error (error, G_SPAWN_EXIT_ERROR, exit_status,
893 _("Child process exited with code %ld"),
905 exec_err_to_g_error (gint en)
911 return G_SPAWN_ERROR_ACCES;
917 return G_SPAWN_ERROR_PERM;
923 return G_SPAWN_ERROR_TOO_BIG;
929 return G_SPAWN_ERROR_NOEXEC;
935 return G_SPAWN_ERROR_NAMETOOLONG;
941 return G_SPAWN_ERROR_NOENT;
947 return G_SPAWN_ERROR_NOMEM;
953 return G_SPAWN_ERROR_NOTDIR;
959 return G_SPAWN_ERROR_LOOP;
965 return G_SPAWN_ERROR_TXTBUSY;
971 return G_SPAWN_ERROR_IO;
977 return G_SPAWN_ERROR_NFILE;
983 return G_SPAWN_ERROR_MFILE;
989 return G_SPAWN_ERROR_INVAL;
995 return G_SPAWN_ERROR_ISDIR;
1001 return G_SPAWN_ERROR_LIBBAD;
1006 return G_SPAWN_ERROR_FAILED;
1012 write_all (gint fd, gconstpointer vbuf, gsize to_write)
1014 gchar *buf = (gchar *) vbuf;
1016 while (to_write > 0)
1018 gssize count = write (fd, buf, to_write);
1036 write_err_and_exit (gint fd, gint msg)
1040 write_all (fd, &msg, sizeof(msg));
1041 write_all (fd, &en, sizeof(en));
1047 set_cloexec (void *data, gint fd)
1049 if (fd >= GPOINTER_TO_INT (data))
1050 fcntl (fd, F_SETFD, FD_CLOEXEC);
1057 fdwalk (int (*cb)(void *data, int fd), void *data)
1063 #ifdef HAVE_SYS_RESOURCE_H
1070 if ((d = opendir("/proc/self/fd"))) {
1073 while ((de = readdir(d))) {
1077 if (de->d_name[0] == '.')
1081 l = strtol(de->d_name, &e, 10);
1082 if (errno != 0 || !e || *e)
1087 if ((glong) fd != l)
1093 if ((res = cb (data, fd)) != 0)
1101 /* If /proc is not mounted or not accessible we fall back to the old
1106 #ifdef HAVE_SYS_RESOURCE_H
1108 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
1109 open_max = rl.rlim_max;
1112 open_max = sysconf (_SC_OPEN_MAX);
1114 for (fd = 0; fd < open_max; fd++)
1115 if ((res = cb (data, fd)) != 0)
1123 sane_dup2 (gint fd1, gint fd2)
1128 ret = dup2 (fd1, fd2);
1129 if (ret < 0 && errno == EINTR)
1136 sane_open (const char *path, gint mode)
1141 ret = open (path, mode);
1142 if (ret < 0 && errno == EINTR)
1157 do_exec (gint child_err_report_fd,
1161 const gchar *working_directory,
1164 gboolean close_descriptors,
1165 gboolean search_path,
1166 gboolean search_path_from_envp,
1167 gboolean stdout_to_null,
1168 gboolean stderr_to_null,
1169 gboolean child_inherits_stdin,
1170 gboolean file_and_argv_zero,
1171 GSpawnChildSetupFunc child_setup,
1174 if (working_directory && chdir (working_directory) < 0)
1175 write_err_and_exit (child_err_report_fd,
1176 CHILD_CHDIR_FAILED);
1178 /* Close all file descriptors but stdin stdout and stderr as
1179 * soon as we exec. Note that this includes
1180 * child_err_report_fd, which keeps the parent from blocking
1181 * forever on the other end of that pipe.
1183 if (close_descriptors)
1185 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1189 /* We need to do child_err_report_fd anyway */
1190 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1193 /* Redirect pipes as required */
1197 /* dup2 can't actually fail here I don't think */
1199 if (sane_dup2 (stdin_fd, 0) < 0)
1200 write_err_and_exit (child_err_report_fd,
1203 /* ignore this if it doesn't work */
1204 close_and_invalidate (&stdin_fd);
1206 else if (!child_inherits_stdin)
1208 /* Keep process from blocking on a read of stdin */
1209 gint read_null = open ("/dev/null", O_RDONLY);
1210 g_assert (read_null != -1);
1211 sane_dup2 (read_null, 0);
1212 close_and_invalidate (&read_null);
1217 /* dup2 can't actually fail here I don't think */
1219 if (sane_dup2 (stdout_fd, 1) < 0)
1220 write_err_and_exit (child_err_report_fd,
1223 /* ignore this if it doesn't work */
1224 close_and_invalidate (&stdout_fd);
1226 else if (stdout_to_null)
1228 gint write_null = sane_open ("/dev/null", O_WRONLY);
1229 g_assert (write_null != -1);
1230 sane_dup2 (write_null, 1);
1231 close_and_invalidate (&write_null);
1236 /* dup2 can't actually fail here I don't think */
1238 if (sane_dup2 (stderr_fd, 2) < 0)
1239 write_err_and_exit (child_err_report_fd,
1242 /* ignore this if it doesn't work */
1243 close_and_invalidate (&stderr_fd);
1245 else if (stderr_to_null)
1247 gint write_null = sane_open ("/dev/null", O_WRONLY);
1248 sane_dup2 (write_null, 2);
1249 close_and_invalidate (&write_null);
1252 /* Call user function just before we exec */
1255 (* child_setup) (user_data);
1259 file_and_argv_zero ? argv + 1 : argv,
1260 envp, search_path, search_path_from_envp);
1263 write_err_and_exit (child_err_report_fd,
1280 if (bytes >= sizeof(gint)*2)
1281 break; /* give up, who knows what happened, should not be
1287 ((gchar*)buf) + bytes,
1288 sizeof(gint) * n_ints_in_buf - bytes);
1289 if (chunk < 0 && errno == EINTR)
1296 /* Some weird shit happened, bail out */
1299 G_SPAWN_ERROR_FAILED,
1300 _("Failed to read from child pipe (%s)"),
1301 g_strerror (errsv));
1305 else if (chunk == 0)
1307 else /* chunk > 0 */
1311 *n_ints_read = (gint)(bytes / sizeof(gint));
1317 fork_exec_with_pipes (gboolean intermediate_child,
1318 const gchar *working_directory,
1321 gboolean close_descriptors,
1322 gboolean search_path,
1323 gboolean search_path_from_envp,
1324 gboolean stdout_to_null,
1325 gboolean stderr_to_null,
1326 gboolean child_inherits_stdin,
1327 gboolean file_and_argv_zero,
1328 GSpawnChildSetupFunc child_setup,
1331 gint *standard_input,
1332 gint *standard_output,
1333 gint *standard_error,
1337 gint stdin_pipe[2] = { -1, -1 };
1338 gint stdout_pipe[2] = { -1, -1 };
1339 gint stderr_pipe[2] = { -1, -1 };
1340 gint child_err_report_pipe[2] = { -1, -1 };
1341 gint child_pid_report_pipe[2] = { -1, -1 };
1344 if (!make_pipe (child_err_report_pipe, error))
1347 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1348 goto cleanup_and_fail;
1350 if (standard_input && !make_pipe (stdin_pipe, error))
1351 goto cleanup_and_fail;
1353 if (standard_output && !make_pipe (stdout_pipe, error))
1354 goto cleanup_and_fail;
1356 if (standard_error && !make_pipe (stderr_pipe, error))
1357 goto cleanup_and_fail;
1368 _("Failed to fork (%s)"),
1369 g_strerror (errsv));
1371 goto cleanup_and_fail;
1375 /* Immediate child. This may or may not be the child that
1376 * actually execs the new process.
1379 /* Reset some signal handlers that we may use */
1380 signal (SIGCHLD, SIG_DFL);
1381 signal (SIGINT, SIG_DFL);
1382 signal (SIGTERM, SIG_DFL);
1383 signal (SIGHUP, SIG_DFL);
1385 /* Be sure we crash if the parent exits
1386 * and we write to the err_report_pipe
1388 signal (SIGPIPE, SIG_DFL);
1390 /* Close the parent's end of the pipes;
1391 * not needed in the close_descriptors case,
1394 close_and_invalidate (&child_err_report_pipe[0]);
1395 close_and_invalidate (&child_pid_report_pipe[0]);
1396 close_and_invalidate (&stdin_pipe[1]);
1397 close_and_invalidate (&stdout_pipe[0]);
1398 close_and_invalidate (&stderr_pipe[0]);
1400 if (intermediate_child)
1402 /* We need to fork an intermediate child that launches the
1403 * final child. The purpose of the intermediate child
1404 * is to exit, so we can waitpid() it immediately.
1405 * Then the grandchild will not become a zombie.
1407 GPid grandchild_pid;
1409 grandchild_pid = fork ();
1411 if (grandchild_pid < 0)
1413 /* report -1 as child PID */
1414 write_all (child_pid_report_pipe[1], &grandchild_pid,
1415 sizeof(grandchild_pid));
1417 write_err_and_exit (child_err_report_pipe[1],
1420 else if (grandchild_pid == 0)
1422 do_exec (child_err_report_pipe[1],
1431 search_path_from_envp,
1434 child_inherits_stdin,
1441 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1442 close_and_invalidate (&child_pid_report_pipe[1]);
1449 /* Just run the child.
1452 do_exec (child_err_report_pipe[1],
1461 search_path_from_envp,
1464 child_inherits_stdin,
1477 /* Close the uncared-about ends of the pipes */
1478 close_and_invalidate (&child_err_report_pipe[1]);
1479 close_and_invalidate (&child_pid_report_pipe[1]);
1480 close_and_invalidate (&stdin_pipe[0]);
1481 close_and_invalidate (&stdout_pipe[1]);
1482 close_and_invalidate (&stderr_pipe[1]);
1484 /* If we had an intermediate child, reap it */
1485 if (intermediate_child)
1488 if (waitpid (pid, &status, 0) < 0)
1492 else if (errno == ECHILD)
1493 ; /* do nothing, child already reaped */
1495 g_warning ("waitpid() should not fail in "
1496 "'fork_exec_with_pipes'");
1501 if (!read_ints (child_err_report_pipe[0],
1504 goto cleanup_and_fail;
1508 /* Error from the child. */
1512 case CHILD_CHDIR_FAILED:
1515 G_SPAWN_ERROR_CHDIR,
1516 _("Failed to change to directory '%s' (%s)"),
1518 g_strerror (buf[1]));
1522 case CHILD_EXEC_FAILED:
1525 exec_err_to_g_error (buf[1]),
1526 _("Failed to execute child process \"%s\" (%s)"),
1528 g_strerror (buf[1]));
1532 case CHILD_DUP2_FAILED:
1535 G_SPAWN_ERROR_FAILED,
1536 _("Failed to redirect output or input of child process (%s)"),
1537 g_strerror (buf[1]));
1541 case CHILD_FORK_FAILED:
1545 _("Failed to fork child process (%s)"),
1546 g_strerror (buf[1]));
1552 G_SPAWN_ERROR_FAILED,
1553 _("Unknown error executing child process \"%s\""),
1558 goto cleanup_and_fail;
1561 /* Get child pid from intermediate child pipe. */
1562 if (intermediate_child)
1566 if (!read_ints (child_pid_report_pipe[0],
1567 buf, 1, &n_ints, error))
1568 goto cleanup_and_fail;
1576 G_SPAWN_ERROR_FAILED,
1577 _("Failed to read enough data from child pid pipe (%s)"),
1578 g_strerror (errsv));
1579 goto cleanup_and_fail;
1583 /* we have the child pid */
1588 /* Success against all odds! return the information */
1589 close_and_invalidate (&child_err_report_pipe[0]);
1590 close_and_invalidate (&child_pid_report_pipe[0]);
1596 *standard_input = stdin_pipe[1];
1597 if (standard_output)
1598 *standard_output = stdout_pipe[0];
1600 *standard_error = stderr_pipe[0];
1607 /* There was an error from the Child, reap the child to avoid it being
1614 if (waitpid (pid, NULL, 0) < 0)
1618 else if (errno == ECHILD)
1619 ; /* do nothing, child already reaped */
1621 g_warning ("waitpid() should not fail in "
1622 "'fork_exec_with_pipes'");
1626 close_and_invalidate (&child_err_report_pipe[0]);
1627 close_and_invalidate (&child_err_report_pipe[1]);
1628 close_and_invalidate (&child_pid_report_pipe[0]);
1629 close_and_invalidate (&child_pid_report_pipe[1]);
1630 close_and_invalidate (&stdin_pipe[0]);
1631 close_and_invalidate (&stdin_pipe[1]);
1632 close_and_invalidate (&stdout_pipe[0]);
1633 close_and_invalidate (&stdout_pipe[1]);
1634 close_and_invalidate (&stderr_pipe[0]);
1635 close_and_invalidate (&stderr_pipe[1]);
1641 make_pipe (gint p[2],
1649 G_SPAWN_ERROR_FAILED,
1650 _("Failed to create pipe for communicating with child process (%s)"),
1651 g_strerror (errsv));
1658 /* Based on execvp from GNU C Library */
1661 script_execute (const gchar *file,
1665 /* Count the arguments. */
1670 /* Construct an argument list for the shell. */
1674 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1676 new_argv[0] = (char *) "/bin/sh";
1677 new_argv[1] = (char *) file;
1680 new_argv[argc + 1] = argv[argc];
1684 /* Execute the shell. */
1686 execve (new_argv[0], new_argv, envp);
1688 execv (new_argv[0], new_argv);
1695 my_strchrnul (const gchar *str, gchar c)
1697 gchar *p = (gchar*) str;
1698 while (*p && (*p != c))
1705 g_execute (const gchar *file,
1708 gboolean search_path,
1709 gboolean search_path_from_envp)
1713 /* We check the simple case first. */
1718 if (!(search_path || search_path_from_envp) || strchr (file, '/') != NULL)
1720 /* Don't search when it contains a slash. */
1722 execve (file, argv, envp);
1726 if (errno == ENOEXEC)
1727 script_execute (file, argv, envp);
1731 gboolean got_eacces = 0;
1732 const gchar *path, *p;
1733 gchar *name, *freeme;
1738 if (search_path_from_envp)
1739 path = g_environ_getenv (envp, "PATH");
1740 if (search_path && path == NULL)
1741 path = g_getenv ("PATH");
1745 /* There is no `PATH' in the environment. The default
1746 * search path in libc is the current directory followed by
1747 * the path `confstr' returns for `_CS_PATH'.
1750 /* In GLib we put . last, for security, and don't use the
1751 * unportable confstr(); UNIX98 does not actually specify
1752 * what to search if PATH is unset. POSIX may, dunno.
1755 path = "/bin:/usr/bin:.";
1758 len = strlen (file) + 1;
1759 pathlen = strlen (path);
1760 freeme = name = g_malloc (pathlen + len + 1);
1762 /* Copy the file name at the top, including '\0' */
1763 memcpy (name + pathlen + 1, file, len);
1764 name = name + pathlen;
1765 /* And add the slash before the filename */
1774 p = my_strchrnul (path, ':');
1777 /* Two adjacent colons, or a colon at the beginning or the end
1778 * of `PATH' means to search the current directory.
1782 startp = memcpy (name - (p - path), path, p - path);
1784 /* Try to execute this name. If it works, execv will not return. */
1786 execve (startp, argv, envp);
1788 execv (startp, argv);
1790 if (errno == ENOEXEC)
1791 script_execute (startp, argv, envp);
1796 /* Record the we got a `Permission denied' error. If we end
1797 * up finding no executable we can use, we want to diagnose
1798 * that we did find one but were denied access.
1811 /* Those errors indicate the file is missing or not executable
1812 * by us, in which case we want to just try the next path
1819 /* Some strange filesystems like AFS return even
1820 * stranger error numbers. They cannot reasonably mean anything
1821 * else so ignore those, too.
1826 /* Some other error means we found an executable file, but
1827 * something went wrong executing it; return the error to our
1834 while (*p++ != '\0');
1836 /* We tried every element and none of them worked. */
1838 /* At least one failure was due to permissions, so report that
1846 /* Return the error from the last attempt (probably ENOENT). */
1851 * g_spawn_close_pid:
1852 * @pid: The process reference to close
1854 * On some platforms, notably Windows, the #GPid type represents a resource
1855 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1856 * is provided for this purpose. It should be used on all platforms, even
1857 * though it doesn't do anything under UNIX.
1860 g_spawn_close_pid (GPid pid)