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 */
49 #include "gstrfuncs.h"
50 #include "gtestutils.h"
57 * @Short_description: process launching
58 * @Title: Spawning Processes
63 static gint g_execute (const gchar *file,
66 gboolean search_path);
68 static gboolean make_pipe (gint p[2],
70 static gboolean fork_exec_with_pipes (gboolean intermediate_child,
71 const gchar *working_directory,
74 gboolean close_descriptors,
76 gboolean stdout_to_null,
77 gboolean stderr_to_null,
78 gboolean child_inherits_stdin,
79 gboolean file_and_argv_zero,
80 GSpawnChildSetupFunc child_setup,
84 gint *standard_output,
89 g_spawn_error_quark (void)
91 return g_quark_from_static_string ("g-exec-error-quark");
96 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
97 * @argv: (array zero-terminated=1): child's argument vector
98 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
99 * @flags: flags from #GSpawnFlags
100 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
101 * @user_data: (closure): user data for @child_setup
102 * @child_pid: (out) (allow-none): return location for child process reference, or %NULL
103 * @error: return location for error
105 * See g_spawn_async_with_pipes() for a full description; this function
106 * simply calls the g_spawn_async_with_pipes() without any pipes.
108 * You should call g_spawn_close_pid() on the returned child process
109 * reference when you don't need it any more.
112 * If you are writing a GTK+ application, and the program you
113 * are spawning is a graphical application, too, then you may
114 * want to use gdk_spawn_on_screen() instead to ensure that
115 * the spawned program opens its windows on the right screen.
118 * <note><para> Note that the returned @child_pid on Windows is a
119 * handle to the child process and not its identifier. Process handles
120 * and process identifiers are different concepts on Windows.
123 * Return value: %TRUE on success, %FALSE if error is set
126 g_spawn_async (const gchar *working_directory,
130 GSpawnChildSetupFunc child_setup,
135 g_return_val_if_fail (argv != NULL, FALSE);
137 return g_spawn_async_with_pipes (working_directory,
147 /* Avoids a danger in threaded situations (calling close()
148 * on a file descriptor twice, and another thread has
149 * re-opened it since the first close)
152 close_and_invalidate (gint *fd)
162 if (ret == -1 && errno == EINTR)
170 /* Some versions of OS X define READ_OK in public headers */
175 READ_FAILED = 0, /* FALSE */
181 read_data (GString *str,
189 bytes = read (fd, buf, 4096);
195 g_string_append_len (str, buf, bytes);
198 else if (errno == EINTR)
207 _("Failed to read data from child process (%s)"),
216 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's
217 * @argv: (array zero-terminated=1): child's argument vector
218 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's
219 * @flags: flags from #GSpawnFlags
220 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
221 * @user_data: (closure): user data for @child_setup
222 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output, or %NULL
223 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child error messages, or %NULL
224 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid(), or %NULL
225 * @error: return location for error, or %NULL
227 * Executes a child synchronously (waits for the child to exit before returning).
228 * All output from the child is stored in @standard_output and @standard_error,
229 * if those parameters are non-%NULL. Note that you must set the
230 * %G_SPAWN_STDOUT_TO_DEV_NULL and %G_SPAWN_STDERR_TO_DEV_NULL flags when
231 * passing %NULL for @standard_output and @standard_error.
232 * If @exit_status is non-%NULL, the exit status of the child is stored
233 * there as it would be returned by waitpid(); standard UNIX macros such
234 * as WIFEXITED() and WEXITSTATUS() must be used to evaluate the exit status.
235 * Note that this function call waitpid() even if @exit_status is %NULL, and
236 * does not accept the %G_SPAWN_DO_NOT_REAP_CHILD flag.
237 * If an error occurs, no data is returned in @standard_output,
238 * @standard_error, or @exit_status.
240 * This function calls g_spawn_async_with_pipes() internally; see that
241 * function for full details on the other parameters and details on
242 * how these functions work on Windows.
244 * Return value: %TRUE on success, %FALSE if an error was set.
247 g_spawn_sync (const gchar *working_directory,
251 GSpawnChildSetupFunc child_setup,
253 gchar **standard_output,
254 gchar **standard_error,
263 GString *outstr = NULL;
264 GString *errstr = NULL;
268 g_return_val_if_fail (argv != NULL, FALSE);
269 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
270 g_return_val_if_fail (standard_output == NULL ||
271 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
272 g_return_val_if_fail (standard_error == NULL ||
273 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
275 /* Just to ensure segfaults if callers try to use
276 * these when an error is reported.
279 *standard_output = NULL;
282 *standard_error = NULL;
284 if (!fork_exec_with_pipes (FALSE,
288 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
289 (flags & G_SPAWN_SEARCH_PATH) != 0,
290 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
291 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
292 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
293 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
298 standard_output ? &outpipe : NULL,
299 standard_error ? &errpipe : NULL,
303 /* Read data from child. */
309 outstr = g_string_new (NULL);
314 errstr = g_string_new (NULL);
317 /* Read data until we get EOF on both pipes. */
326 FD_SET (outpipe, &fds);
328 FD_SET (errpipe, &fds);
330 ret = select (MAX (outpipe, errpipe) + 1,
333 NULL /* no timeout */);
347 _("Unexpected error in select() reading data from a child process (%s)"),
353 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
355 switch (read_data (outstr, outpipe, error))
361 close_and_invalidate (&outpipe);
372 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
374 switch (read_data (errstr, errpipe, error))
380 close_and_invalidate (&errpipe);
392 /* These should only be open still if we had an error. */
395 close_and_invalidate (&outpipe);
397 close_and_invalidate (&errpipe);
399 /* Wait for child to exit, even if we have
404 ret = waitpid (pid, &status, 0);
410 else if (errno == ECHILD)
414 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.");
418 /* We don't need the exit status. */
423 if (!failed) /* avoid error pileups */
432 _("Unexpected error in waitpid() (%s)"),
441 g_string_free (outstr, TRUE);
443 g_string_free (errstr, TRUE);
450 *exit_status = status;
453 *standard_output = g_string_free (outstr, FALSE);
456 *standard_error = g_string_free (errstr, FALSE);
463 * g_spawn_async_with_pipes:
464 * @working_directory: (allow-none): child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
465 * @argv: (array zero-terminated=1): child's argument vector, in the GLib file name encoding
466 * @envp: (array zero-terminated=1) (allow-none): child's environment, or %NULL to inherit parent's, in the GLib file name encoding
467 * @flags: flags from #GSpawnFlags
468 * @child_setup: (scope async) (allow-none): function to run in the child just before exec()
469 * @user_data: (closure): user data for @child_setup
470 * @child_pid: (out) (allow-none): return location for child process ID, or %NULL
471 * @standard_input: (out) (allow-none): return location for file descriptor to write to child's stdin, or %NULL
472 * @standard_output: (out) (allow-none): return location for file descriptor to read child's stdout, or %NULL
473 * @standard_error: (out) (allow-none): return location for file descriptor to read child's stderr, or %NULL
474 * @error: return location for error
476 * Executes a child program asynchronously (your program will not
477 * block waiting for the child to exit). The child program is
478 * specified by the only argument that must be provided, @argv. @argv
479 * should be a %NULL-terminated array of strings, to be passed as the
480 * argument vector for the child. The first string in @argv is of
481 * course the name of the program to execute. By default, the name of
482 * the program must be a full path; the <envar>PATH</envar> shell variable
483 * will only be searched if you pass the %G_SPAWN_SEARCH_PATH flag.
485 * On Windows, note that all the string or string vector arguments to
486 * this function and the other g_spawn*() functions are in UTF-8, the
487 * GLib file name encoding. Unicode characters that are not part of
488 * the system codepage passed in these arguments will be correctly
489 * available in the spawned program only if it uses wide character API
490 * to retrieve its command line. For C programs built with Microsoft's
491 * tools it is enough to make the program have a wmain() instead of
492 * main(). wmain() has a wide character argument vector as parameter.
494 * At least currently, mingw doesn't support wmain(), so if you use
495 * mingw to develop the spawned program, it will have to call the
496 * undocumented function __wgetmainargs() to get the wide character
497 * argument vector and environment. See gspawn-win32-helper.c in the
498 * GLib sources or init.c in the mingw runtime sources for a prototype
499 * for that function. Alternatively, you can retrieve the Win32 system
500 * level wide character command line passed to the spawned program
501 * using the GetCommandLineW() function.
503 * On Windows the low-level child process creation API
504 * <function>CreateProcess()</function> doesn't use argument vectors,
505 * but a command line. The C runtime library's
506 * <function>spawn*()</function> family of functions (which
507 * g_spawn_async_with_pipes() eventually calls) paste the argument
508 * vector elements together into a command line, and the C runtime startup code
509 * does a corresponding reconstruction of an argument vector from the
510 * command line, to be passed to main(). Complications arise when you have
511 * argument vector elements that contain spaces of double quotes. The
512 * <function>spawn*()</function> functions don't do any quoting or
513 * escaping, but on the other hand the startup code does do unquoting
514 * and unescaping in order to enable receiving arguments with embedded
515 * spaces or double quotes. To work around this asymmetry,
516 * g_spawn_async_with_pipes() will do quoting and escaping on argument
517 * vector elements that need it before calling the C runtime
520 * The returned @child_pid on Windows is a handle to the child
521 * process, not its identifier. Process handles and process
522 * identifiers are different concepts on Windows.
524 * @envp is a %NULL-terminated array of strings, where each string
525 * has the form <literal>KEY=VALUE</literal>. This will become
526 * the child's environment. If @envp is %NULL, the child inherits its
527 * parent's environment.
529 * @flags should be the bitwise OR of any flags you want to affect the
530 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that
531 * the child will not automatically be reaped; you must use a
532 * #GChildWatch source to be notified about the death of the child
533 * process. Eventually you must call g_spawn_close_pid() on the
534 * @child_pid, in order to free resources which may be associated
535 * with the child process. (On Unix, using a #GChildWatch source is
536 * equivalent to calling waitpid() or handling the %SIGCHLD signal
537 * manually. On Windows, calling g_spawn_close_pid() is equivalent
538 * to calling CloseHandle() on the process handle returned in
541 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
542 * descriptors will be inherited by the child; otherwise all
543 * descriptors except stdin/stdout/stderr will be closed before
544 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
545 * means that <literal>argv[0]</literal> need not be an absolute path, it
546 * will be looked for in the user's <envar>PATH</envar>.
547 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
548 * be discarded, instead of going to the same location as the parent's
549 * standard output. If you use this flag, @standard_output must be %NULL.
550 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
551 * will be discarded, instead of going to the same location as the parent's
552 * standard error. If you use this flag, @standard_error must be %NULL.
553 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
554 * standard input (by default, the child's standard input is attached to
555 * /dev/null). If you use this flag, @standard_input must be %NULL.
556 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
557 * the file to execute, while the remaining elements are the
558 * actual argument vector to pass to the file. Normally
559 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
560 * passes all of @argv to the child.
562 * @child_setup and @user_data are a function and user data. On POSIX
563 * platforms, the function is called in the child after GLib has
564 * performed all the setup it plans to perform (including creating
565 * pipes, closing file descriptors, etc.) but before calling
566 * exec(). That is, @child_setup is called just
567 * before calling exec() in the child. Obviously
568 * actions taken in this function will only affect the child, not the
571 * On Windows, there is no separate fork() and exec()
572 * functionality. Child processes are created and run with a single
573 * API call, CreateProcess(). There is no sensible thing @child_setup
574 * could be used for on Windows so it is ignored and not called.
576 * If non-%NULL, @child_pid will on Unix be filled with the child's
577 * process ID. You can use the process ID to send signals to the
578 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
579 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
580 * filled with a handle to the child process only if you specified the
581 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
582 * process using the Win32 API, for example wait for its termination
583 * with the <function>WaitFor*()</function> functions, or examine its
584 * exit code with GetExitCodeProcess(). You should close the handle
585 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
587 * If non-%NULL, the @standard_input, @standard_output, @standard_error
588 * locations will be filled with file descriptors for writing to the child's
589 * standard input or reading from its standard output or standard error.
590 * The caller of g_spawn_async_with_pipes() must close these file descriptors
591 * when they are no longer in use. If these parameters are %NULL, the corresponding
592 * pipe won't be created.
594 * If @standard_input is NULL, the child's standard input is attached to
595 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
597 * If @standard_error is NULL, the child's standard error goes to the same
598 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
601 * If @standard_output is NULL, the child's standard output goes to the same
602 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
605 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
606 * If an error is set, the function returns %FALSE. Errors
607 * are reported even if they occur in the child (for example if the
608 * executable in <literal>argv[0]</literal> is not found). Typically
609 * the <literal>message</literal> field of returned errors should be displayed
610 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
612 * If an error occurs, @child_pid, @standard_input, @standard_output,
613 * and @standard_error will not be filled with valid values.
615 * If @child_pid is not %NULL and an error does not occur then the returned
616 * process reference must be closed using g_spawn_close_pid().
619 * If you are writing a GTK+ application, and the program you
620 * are spawning is a graphical application, too, then you may
621 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
622 * the spawned program opens its windows on the right screen.
625 * Return value: %TRUE on success, %FALSE if an error was set
628 g_spawn_async_with_pipes (const gchar *working_directory,
632 GSpawnChildSetupFunc child_setup,
635 gint *standard_input,
636 gint *standard_output,
637 gint *standard_error,
640 g_return_val_if_fail (argv != NULL, FALSE);
641 g_return_val_if_fail (standard_output == NULL ||
642 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
643 g_return_val_if_fail (standard_error == NULL ||
644 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
645 /* can't inherit stdin if we have an input pipe. */
646 g_return_val_if_fail (standard_input == NULL ||
647 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
649 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
653 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
654 (flags & G_SPAWN_SEARCH_PATH) != 0,
655 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
656 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
657 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
658 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
669 * g_spawn_command_line_sync:
670 * @command_line: a command line
671 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
672 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
673 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
674 * @error: return location for errors
676 * A simple version of g_spawn_sync() with little-used parameters
677 * removed, taking a command line instead of an argument vector. See
678 * g_spawn_sync() for full details. @command_line will be parsed by
679 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
680 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
681 * implications, so consider using g_spawn_sync() directly if
682 * appropriate. Possible errors are those from g_spawn_sync() and those
683 * from g_shell_parse_argv().
685 * If @exit_status is non-%NULL, the exit status of the child is stored there as
686 * it would be returned by waitpid(); standard UNIX macros such as WIFEXITED()
687 * and WEXITSTATUS() must be used to evaluate the exit status.
689 * On Windows, please note the implications of g_shell_parse_argv()
690 * parsing @command_line. Parsing is done according to Unix shell rules, not
691 * Windows command interpreter rules.
692 * Space is a separator, and backslashes are
693 * special. Thus you cannot simply pass a @command_line containing
694 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
695 * the backslashes will be eaten, and the space will act as a
696 * separator. You need to enclose such paths with single quotes, like
697 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
699 * Return value: %TRUE on success, %FALSE if an error was set
702 g_spawn_command_line_sync (const gchar *command_line,
703 gchar **standard_output,
704 gchar **standard_error,
711 g_return_val_if_fail (command_line != NULL, FALSE);
713 if (!g_shell_parse_argv (command_line,
718 retval = g_spawn_sync (NULL,
734 * g_spawn_command_line_async:
735 * @command_line: a command line
736 * @error: return location for errors
738 * A simple version of g_spawn_async() that parses a command line with
739 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
740 * command line in the background. Unlike g_spawn_async(), the
741 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
742 * that %G_SPAWN_SEARCH_PATH can have security implications, so
743 * consider using g_spawn_async() directly if appropriate. Possible
744 * errors are those from g_shell_parse_argv() and g_spawn_async().
746 * The same concerns on Windows apply as for g_spawn_command_line_sync().
748 * Return value: %TRUE on success, %FALSE if error is set.
751 g_spawn_command_line_async (const gchar *command_line,
757 g_return_val_if_fail (command_line != NULL, FALSE);
759 if (!g_shell_parse_argv (command_line,
764 retval = g_spawn_async (NULL,
778 exec_err_to_g_error (gint en)
784 return G_SPAWN_ERROR_ACCES;
790 return G_SPAWN_ERROR_PERM;
796 return G_SPAWN_ERROR_2BIG;
802 return G_SPAWN_ERROR_NOEXEC;
808 return G_SPAWN_ERROR_NAMETOOLONG;
814 return G_SPAWN_ERROR_NOENT;
820 return G_SPAWN_ERROR_NOMEM;
826 return G_SPAWN_ERROR_NOTDIR;
832 return G_SPAWN_ERROR_LOOP;
838 return G_SPAWN_ERROR_TXTBUSY;
844 return G_SPAWN_ERROR_IO;
850 return G_SPAWN_ERROR_NFILE;
856 return G_SPAWN_ERROR_MFILE;
862 return G_SPAWN_ERROR_INVAL;
868 return G_SPAWN_ERROR_ISDIR;
874 return G_SPAWN_ERROR_LIBBAD;
879 return G_SPAWN_ERROR_FAILED;
885 write_all (gint fd, gconstpointer vbuf, gsize to_write)
887 gchar *buf = (gchar *) vbuf;
891 gssize count = write (fd, buf, to_write);
909 write_err_and_exit (gint fd, gint msg)
913 write_all (fd, &msg, sizeof(msg));
914 write_all (fd, &en, sizeof(en));
920 set_cloexec (void *data, gint fd)
922 if (fd >= GPOINTER_TO_INT (data))
923 fcntl (fd, F_SETFD, FD_CLOEXEC);
930 fdwalk (int (*cb)(void *data, int fd), void *data)
936 #ifdef HAVE_SYS_RESOURCE_H
943 if ((d = opendir("/proc/self/fd"))) {
946 while ((de = readdir(d))) {
950 if (de->d_name[0] == '.')
954 l = strtol(de->d_name, &e, 10);
955 if (errno != 0 || !e || *e)
966 if ((res = cb (data, fd)) != 0)
974 /* If /proc is not mounted or not accessible we fall back to the old
979 #ifdef HAVE_SYS_RESOURCE_H
981 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
982 open_max = rl.rlim_max;
985 open_max = sysconf (_SC_OPEN_MAX);
987 for (fd = 0; fd < open_max; fd++)
988 if ((res = cb (data, fd)) != 0)
996 sane_dup2 (gint fd1, gint fd2)
1001 ret = dup2 (fd1, fd2);
1002 if (ret < 0 && errno == EINTR)
1009 sane_open (const char *path, gint mode)
1014 ret = open (path, mode);
1015 if (ret < 0 && errno == EINTR)
1030 do_exec (gint child_err_report_fd,
1034 const gchar *working_directory,
1037 gboolean close_descriptors,
1038 gboolean search_path,
1039 gboolean stdout_to_null,
1040 gboolean stderr_to_null,
1041 gboolean child_inherits_stdin,
1042 gboolean file_and_argv_zero,
1043 GSpawnChildSetupFunc child_setup,
1046 if (working_directory && chdir (working_directory) < 0)
1047 write_err_and_exit (child_err_report_fd,
1048 CHILD_CHDIR_FAILED);
1050 /* Close all file descriptors but stdin stdout and stderr as
1051 * soon as we exec. Note that this includes
1052 * child_err_report_fd, which keeps the parent from blocking
1053 * forever on the other end of that pipe.
1055 if (close_descriptors)
1057 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1061 /* We need to do child_err_report_fd anyway */
1062 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1065 /* Redirect pipes as required */
1069 /* dup2 can't actually fail here I don't think */
1071 if (sane_dup2 (stdin_fd, 0) < 0)
1072 write_err_and_exit (child_err_report_fd,
1075 /* ignore this if it doesn't work */
1076 close_and_invalidate (&stdin_fd);
1078 else if (!child_inherits_stdin)
1080 /* Keep process from blocking on a read of stdin */
1081 gint read_null = open ("/dev/null", O_RDONLY);
1082 sane_dup2 (read_null, 0);
1083 close_and_invalidate (&read_null);
1088 /* dup2 can't actually fail here I don't think */
1090 if (sane_dup2 (stdout_fd, 1) < 0)
1091 write_err_and_exit (child_err_report_fd,
1094 /* ignore this if it doesn't work */
1095 close_and_invalidate (&stdout_fd);
1097 else if (stdout_to_null)
1099 gint write_null = sane_open ("/dev/null", O_WRONLY);
1100 sane_dup2 (write_null, 1);
1101 close_and_invalidate (&write_null);
1106 /* dup2 can't actually fail here I don't think */
1108 if (sane_dup2 (stderr_fd, 2) < 0)
1109 write_err_and_exit (child_err_report_fd,
1112 /* ignore this if it doesn't work */
1113 close_and_invalidate (&stderr_fd);
1115 else if (stderr_to_null)
1117 gint write_null = sane_open ("/dev/null", O_WRONLY);
1118 sane_dup2 (write_null, 2);
1119 close_and_invalidate (&write_null);
1122 /* Call user function just before we exec */
1125 (* child_setup) (user_data);
1129 file_and_argv_zero ? argv + 1 : argv,
1133 write_err_and_exit (child_err_report_fd,
1150 if (bytes >= sizeof(gint)*2)
1151 break; /* give up, who knows what happened, should not be
1157 ((gchar*)buf) + bytes,
1158 sizeof(gint) * n_ints_in_buf - bytes);
1159 if (chunk < 0 && errno == EINTR)
1166 /* Some weird shit happened, bail out */
1169 G_SPAWN_ERROR_FAILED,
1170 _("Failed to read from child pipe (%s)"),
1171 g_strerror (errsv));
1175 else if (chunk == 0)
1177 else /* chunk > 0 */
1181 *n_ints_read = (gint)(bytes / sizeof(gint));
1187 fork_exec_with_pipes (gboolean intermediate_child,
1188 const gchar *working_directory,
1191 gboolean close_descriptors,
1192 gboolean search_path,
1193 gboolean stdout_to_null,
1194 gboolean stderr_to_null,
1195 gboolean child_inherits_stdin,
1196 gboolean file_and_argv_zero,
1197 GSpawnChildSetupFunc child_setup,
1200 gint *standard_input,
1201 gint *standard_output,
1202 gint *standard_error,
1206 gint stdin_pipe[2] = { -1, -1 };
1207 gint stdout_pipe[2] = { -1, -1 };
1208 gint stderr_pipe[2] = { -1, -1 };
1209 gint child_err_report_pipe[2] = { -1, -1 };
1210 gint child_pid_report_pipe[2] = { -1, -1 };
1213 if (!make_pipe (child_err_report_pipe, error))
1216 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1217 goto cleanup_and_fail;
1219 if (standard_input && !make_pipe (stdin_pipe, error))
1220 goto cleanup_and_fail;
1222 if (standard_output && !make_pipe (stdout_pipe, error))
1223 goto cleanup_and_fail;
1225 if (standard_error && !make_pipe (stderr_pipe, error))
1226 goto cleanup_and_fail;
1237 _("Failed to fork (%s)"),
1238 g_strerror (errsv));
1240 goto cleanup_and_fail;
1244 /* Immediate child. This may or may not be the child that
1245 * actually execs the new process.
1248 /* Reset some signal handlers that we may use */
1249 signal (SIGCHLD, SIG_DFL);
1250 signal (SIGINT, SIG_DFL);
1251 signal (SIGTERM, SIG_DFL);
1252 signal (SIGHUP, SIG_DFL);
1254 /* Be sure we crash if the parent exits
1255 * and we write to the err_report_pipe
1257 signal (SIGPIPE, SIG_DFL);
1259 /* Close the parent's end of the pipes;
1260 * not needed in the close_descriptors case,
1263 close_and_invalidate (&child_err_report_pipe[0]);
1264 close_and_invalidate (&child_pid_report_pipe[0]);
1265 close_and_invalidate (&stdin_pipe[1]);
1266 close_and_invalidate (&stdout_pipe[0]);
1267 close_and_invalidate (&stderr_pipe[0]);
1269 if (intermediate_child)
1271 /* We need to fork an intermediate child that launches the
1272 * final child. The purpose of the intermediate child
1273 * is to exit, so we can waitpid() it immediately.
1274 * Then the grandchild will not become a zombie.
1276 GPid grandchild_pid;
1278 grandchild_pid = fork ();
1280 if (grandchild_pid < 0)
1282 /* report -1 as child PID */
1283 write_all (child_pid_report_pipe[1], &grandchild_pid,
1284 sizeof(grandchild_pid));
1286 write_err_and_exit (child_err_report_pipe[1],
1289 else if (grandchild_pid == 0)
1291 do_exec (child_err_report_pipe[1],
1302 child_inherits_stdin,
1309 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1310 close_and_invalidate (&child_pid_report_pipe[1]);
1317 /* Just run the child.
1320 do_exec (child_err_report_pipe[1],
1331 child_inherits_stdin,
1344 /* Close the uncared-about ends of the pipes */
1345 close_and_invalidate (&child_err_report_pipe[1]);
1346 close_and_invalidate (&child_pid_report_pipe[1]);
1347 close_and_invalidate (&stdin_pipe[0]);
1348 close_and_invalidate (&stdout_pipe[1]);
1349 close_and_invalidate (&stderr_pipe[1]);
1351 /* If we had an intermediate child, reap it */
1352 if (intermediate_child)
1355 if (waitpid (pid, &status, 0) < 0)
1359 else if (errno == ECHILD)
1360 ; /* do nothing, child already reaped */
1362 g_warning ("waitpid() should not fail in "
1363 "'fork_exec_with_pipes'");
1368 if (!read_ints (child_err_report_pipe[0],
1371 goto cleanup_and_fail;
1375 /* Error from the child. */
1379 case CHILD_CHDIR_FAILED:
1382 G_SPAWN_ERROR_CHDIR,
1383 _("Failed to change to directory '%s' (%s)"),
1385 g_strerror (buf[1]));
1389 case CHILD_EXEC_FAILED:
1392 exec_err_to_g_error (buf[1]),
1393 _("Failed to execute child process \"%s\" (%s)"),
1395 g_strerror (buf[1]));
1399 case CHILD_DUP2_FAILED:
1402 G_SPAWN_ERROR_FAILED,
1403 _("Failed to redirect output or input of child process (%s)"),
1404 g_strerror (buf[1]));
1408 case CHILD_FORK_FAILED:
1412 _("Failed to fork child process (%s)"),
1413 g_strerror (buf[1]));
1419 G_SPAWN_ERROR_FAILED,
1420 _("Unknown error executing child process \"%s\""),
1425 goto cleanup_and_fail;
1428 /* Get child pid from intermediate child pipe. */
1429 if (intermediate_child)
1433 if (!read_ints (child_pid_report_pipe[0],
1434 buf, 1, &n_ints, error))
1435 goto cleanup_and_fail;
1443 G_SPAWN_ERROR_FAILED,
1444 _("Failed to read enough data from child pid pipe (%s)"),
1445 g_strerror (errsv));
1446 goto cleanup_and_fail;
1450 /* we have the child pid */
1455 /* Success against all odds! return the information */
1456 close_and_invalidate (&child_err_report_pipe[0]);
1457 close_and_invalidate (&child_pid_report_pipe[0]);
1463 *standard_input = stdin_pipe[1];
1464 if (standard_output)
1465 *standard_output = stdout_pipe[0];
1467 *standard_error = stderr_pipe[0];
1474 /* There was an error from the Child, reap the child to avoid it being
1481 if (waitpid (pid, NULL, 0) < 0)
1485 else if (errno == ECHILD)
1486 ; /* do nothing, child already reaped */
1488 g_warning ("waitpid() should not fail in "
1489 "'fork_exec_with_pipes'");
1493 close_and_invalidate (&child_err_report_pipe[0]);
1494 close_and_invalidate (&child_err_report_pipe[1]);
1495 close_and_invalidate (&child_pid_report_pipe[0]);
1496 close_and_invalidate (&child_pid_report_pipe[1]);
1497 close_and_invalidate (&stdin_pipe[0]);
1498 close_and_invalidate (&stdin_pipe[1]);
1499 close_and_invalidate (&stdout_pipe[0]);
1500 close_and_invalidate (&stdout_pipe[1]);
1501 close_and_invalidate (&stderr_pipe[0]);
1502 close_and_invalidate (&stderr_pipe[1]);
1508 make_pipe (gint p[2],
1516 G_SPAWN_ERROR_FAILED,
1517 _("Failed to create pipe for communicating with child process (%s)"),
1518 g_strerror (errsv));
1525 /* Based on execvp from GNU C Library */
1528 script_execute (const gchar *file,
1531 gboolean search_path)
1533 /* Count the arguments. */
1538 /* Construct an argument list for the shell. */
1542 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1544 new_argv[0] = (char *) "/bin/sh";
1545 new_argv[1] = (char *) file;
1548 new_argv[argc + 1] = argv[argc];
1552 /* Execute the shell. */
1554 execve (new_argv[0], new_argv, envp);
1556 execv (new_argv[0], new_argv);
1563 my_strchrnul (const gchar *str, gchar c)
1565 gchar *p = (gchar*) str;
1566 while (*p && (*p != c))
1573 g_execute (const gchar *file,
1576 gboolean search_path)
1580 /* We check the simple case first. */
1585 if (!search_path || strchr (file, '/') != NULL)
1587 /* Don't search when it contains a slash. */
1589 execve (file, argv, envp);
1593 if (errno == ENOEXEC)
1594 script_execute (file, argv, envp, FALSE);
1598 gboolean got_eacces = 0;
1599 const gchar *path, *p;
1600 gchar *name, *freeme;
1604 path = g_getenv ("PATH");
1607 /* There is no `PATH' in the environment. The default
1608 * search path in libc is the current directory followed by
1609 * the path `confstr' returns for `_CS_PATH'.
1612 /* In GLib we put . last, for security, and don't use the
1613 * unportable confstr(); UNIX98 does not actually specify
1614 * what to search if PATH is unset. POSIX may, dunno.
1617 path = "/bin:/usr/bin:.";
1620 len = strlen (file) + 1;
1621 pathlen = strlen (path);
1622 freeme = name = g_malloc (pathlen + len + 1);
1624 /* Copy the file name at the top, including '\0' */
1625 memcpy (name + pathlen + 1, file, len);
1626 name = name + pathlen;
1627 /* And add the slash before the filename */
1636 p = my_strchrnul (path, ':');
1639 /* Two adjacent colons, or a colon at the beginning or the end
1640 * of `PATH' means to search the current directory.
1644 startp = memcpy (name - (p - path), path, p - path);
1646 /* Try to execute this name. If it works, execv will not return. */
1648 execve (startp, argv, envp);
1650 execv (startp, argv);
1652 if (errno == ENOEXEC)
1653 script_execute (startp, argv, envp, search_path);
1658 /* Record the we got a `Permission denied' error. If we end
1659 * up finding no executable we can use, we want to diagnose
1660 * that we did find one but were denied access.
1673 /* Those errors indicate the file is missing or not executable
1674 * by us, in which case we want to just try the next path
1680 /* Some other error means we found an executable file, but
1681 * something went wrong executing it; return the error to our
1688 while (*p++ != '\0');
1690 /* We tried every element and none of them worked. */
1692 /* At least one failure was due to permissions, so report that
1700 /* Return the error from the last attempt (probably ENOENT). */
1705 * g_spawn_close_pid:
1706 * @pid: The process reference to close
1708 * On some platforms, notably Windows, the #GPid type represents a resource
1709 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1710 * is provided for this purpose. It should be used on all platforms, even
1711 * though it doesn't do anything under UNIX.
1714 g_spawn_close_pid (GPid pid)