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
)