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 the
531 * child will not automatically be reaped; you must use a child watch to
532 * be notified about the death of the child process. Eventually you must
533 * call g_spawn_close_pid() on the @child_pid, in order to free
534 * resources which may be associated with the child process. (On Unix,
535 * using a child watch is equivalent to calling waitpid() or handling
536 * the %SIGCHLD signal manually. On Windows, calling g_spawn_close_pid()
537 * is equivalent to calling CloseHandle() on the process handle returned
538 * in @child_pid). See g_child_watch_add().
540 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
541 * descriptors will be inherited by the child; otherwise all
542 * descriptors except stdin/stdout/stderr will be closed before
543 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
544 * means that <literal>argv[0]</literal> need not be an absolute path, it
545 * will be looked for in the user's <envar>PATH</envar>.
546 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
547 * be discarded, instead of going to the same location as the parent's
548 * standard output. If you use this flag, @standard_output must be %NULL.
549 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
550 * will be discarded, instead of going to the same location as the parent's
551 * standard error. If you use this flag, @standard_error must be %NULL.
552 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
553 * standard input (by default, the child's standard input is attached to
554 * /dev/null). If you use this flag, @standard_input must be %NULL.
555 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
556 * the file to execute, while the remaining elements are the
557 * actual argument vector to pass to the file. Normally
558 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
559 * passes all of @argv to the child.
561 * @child_setup and @user_data are a function and user data. On POSIX
562 * platforms, the function is called in the child after GLib has
563 * performed all the setup it plans to perform (including creating
564 * pipes, closing file descriptors, etc.) but before calling
565 * exec(). That is, @child_setup is called just
566 * before calling exec() in the child. Obviously
567 * actions taken in this function will only affect the child, not the
570 * On Windows, there is no separate fork() and exec()
571 * functionality. Child processes are created and run with a single
572 * API call, CreateProcess(). There is no sensible thing @child_setup
573 * could be used for on Windows so it is ignored and not called.
575 * If non-%NULL, @child_pid will on Unix be filled with the child's
576 * process ID. You can use the process ID to send signals to the
577 * child, or to use g_child_watch_add() (or waitpid()) if you specified the
578 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
579 * filled with a handle to the child process only if you specified the
580 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
581 * process using the Win32 API, for example wait for its termination
582 * with the <function>WaitFor*()</function> functions, or examine its
583 * exit code with GetExitCodeProcess(). You should close the handle
584 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
586 * If non-%NULL, the @standard_input, @standard_output, @standard_error
587 * locations will be filled with file descriptors for writing to the child's
588 * standard input or reading from its standard output or standard error.
589 * The caller of g_spawn_async_with_pipes() must close these file descriptors
590 * when they are no longer in use. If these parameters are %NULL, the corresponding
591 * pipe won't be created.
593 * If @standard_input is NULL, the child's standard input is attached to
594 * /dev/null unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
596 * If @standard_error is NULL, the child's standard error goes to the same
597 * location as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL
600 * If @standard_output is NULL, the child's standard output goes to the same
601 * location as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL
604 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
605 * If an error is set, the function returns %FALSE. Errors
606 * are reported even if they occur in the child (for example if the
607 * executable in <literal>argv[0]</literal> is not found). Typically
608 * the <literal>message</literal> field of returned errors should be displayed
609 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
611 * If an error occurs, @child_pid, @standard_input, @standard_output,
612 * and @standard_error will not be filled with valid values.
614 * If @child_pid is not %NULL and an error does not occur then the returned
615 * process reference must be closed using g_spawn_close_pid().
618 * If you are writing a GTK+ application, and the program you
619 * are spawning is a graphical application, too, then you may
620 * want to use gdk_spawn_on_screen_with_pipes() instead to ensure that
621 * the spawned program opens its windows on the right screen.
624 * Return value: %TRUE on success, %FALSE if an error was set
627 g_spawn_async_with_pipes (const gchar *working_directory,
631 GSpawnChildSetupFunc child_setup,
634 gint *standard_input,
635 gint *standard_output,
636 gint *standard_error,
639 g_return_val_if_fail (argv != NULL, FALSE);
640 g_return_val_if_fail (standard_output == NULL ||
641 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
642 g_return_val_if_fail (standard_error == NULL ||
643 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
644 /* can't inherit stdin if we have an input pipe. */
645 g_return_val_if_fail (standard_input == NULL ||
646 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
648 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
652 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
653 (flags & G_SPAWN_SEARCH_PATH) != 0,
654 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
655 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
656 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
657 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
668 * g_spawn_command_line_sync:
669 * @command_line: a command line
670 * @standard_output: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child output
671 * @standard_error: (out) (array zero-terminated=1) (element-type guint8) (allow-none): return location for child errors
672 * @exit_status: (out) (allow-none): return location for child exit status, as returned by waitpid()
673 * @error: return location for errors
675 * A simple version of g_spawn_sync() with little-used parameters
676 * removed, taking a command line instead of an argument vector. See
677 * g_spawn_sync() for full details. @command_line will be parsed by
678 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
679 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
680 * implications, so consider using g_spawn_sync() directly if
681 * appropriate. Possible errors are those from g_spawn_sync() and those
682 * from g_shell_parse_argv().
684 * If @exit_status is non-%NULL, the exit status of the child is stored there as
685 * it would be returned by waitpid(); standard UNIX macros such as WIFEXITED()
686 * and WEXITSTATUS() must be used to evaluate the exit status.
688 * On Windows, please note the implications of g_shell_parse_argv()
689 * parsing @command_line. Parsing is done according to Unix shell rules, not
690 * Windows command interpreter rules.
691 * Space is a separator, and backslashes are
692 * special. Thus you cannot simply pass a @command_line containing
693 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
694 * the backslashes will be eaten, and the space will act as a
695 * separator. You need to enclose such paths with single quotes, like
696 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
698 * Return value: %TRUE on success, %FALSE if an error was set
701 g_spawn_command_line_sync (const gchar *command_line,
702 gchar **standard_output,
703 gchar **standard_error,
710 g_return_val_if_fail (command_line != NULL, FALSE);
712 if (!g_shell_parse_argv (command_line,
717 retval = g_spawn_sync (NULL,
733 * g_spawn_command_line_async:
734 * @command_line: a command line
735 * @error: return location for errors
737 * A simple version of g_spawn_async() that parses a command line with
738 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
739 * command line in the background. Unlike g_spawn_async(), the
740 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
741 * that %G_SPAWN_SEARCH_PATH can have security implications, so
742 * consider using g_spawn_async() directly if appropriate. Possible
743 * errors are those from g_shell_parse_argv() and g_spawn_async().
745 * The same concerns on Windows apply as for g_spawn_command_line_sync().
747 * Return value: %TRUE on success, %FALSE if error is set.
750 g_spawn_command_line_async (const gchar *command_line,
756 g_return_val_if_fail (command_line != NULL, FALSE);
758 if (!g_shell_parse_argv (command_line,
763 retval = g_spawn_async (NULL,
777 exec_err_to_g_error (gint en)
783 return G_SPAWN_ERROR_ACCES;
789 return G_SPAWN_ERROR_PERM;
795 return G_SPAWN_ERROR_2BIG;
801 return G_SPAWN_ERROR_NOEXEC;
807 return G_SPAWN_ERROR_NAMETOOLONG;
813 return G_SPAWN_ERROR_NOENT;
819 return G_SPAWN_ERROR_NOMEM;
825 return G_SPAWN_ERROR_NOTDIR;
831 return G_SPAWN_ERROR_LOOP;
837 return G_SPAWN_ERROR_TXTBUSY;
843 return G_SPAWN_ERROR_IO;
849 return G_SPAWN_ERROR_NFILE;
855 return G_SPAWN_ERROR_MFILE;
861 return G_SPAWN_ERROR_INVAL;
867 return G_SPAWN_ERROR_ISDIR;
873 return G_SPAWN_ERROR_LIBBAD;
878 return G_SPAWN_ERROR_FAILED;
884 write_all (gint fd, gconstpointer vbuf, gsize to_write)
886 gchar *buf = (gchar *) vbuf;
890 gssize count = write (fd, buf, to_write);
908 write_err_and_exit (gint fd, gint msg)
912 write_all (fd, &msg, sizeof(msg));
913 write_all (fd, &en, sizeof(en));
919 set_cloexec (void *data, gint fd)
921 if (fd >= GPOINTER_TO_INT (data))
922 fcntl (fd, F_SETFD, FD_CLOEXEC);
929 fdwalk (int (*cb)(void *data, int fd), void *data)
935 #ifdef HAVE_SYS_RESOURCE_H
942 if ((d = opendir("/proc/self/fd"))) {
945 while ((de = readdir(d))) {
949 if (de->d_name[0] == '.')
953 l = strtol(de->d_name, &e, 10);
954 if (errno != 0 || !e || *e)
965 if ((res = cb (data, fd)) != 0)
973 /* If /proc is not mounted or not accessible we fall back to the old
978 #ifdef HAVE_SYS_RESOURCE_H
980 if (getrlimit(RLIMIT_NOFILE, &rl) == 0 && rl.rlim_max != RLIM_INFINITY)
981 open_max = rl.rlim_max;
984 open_max = sysconf (_SC_OPEN_MAX);
986 for (fd = 0; fd < open_max; fd++)
987 if ((res = cb (data, fd)) != 0)
995 sane_dup2 (gint fd1, gint fd2)
1000 ret = dup2 (fd1, fd2);
1001 if (ret < 0 && errno == EINTR)
1008 sane_open (const char *path, gint mode)
1013 ret = open (path, mode);
1014 if (ret < 0 && errno == EINTR)
1029 do_exec (gint child_err_report_fd,
1033 const gchar *working_directory,
1036 gboolean close_descriptors,
1037 gboolean search_path,
1038 gboolean stdout_to_null,
1039 gboolean stderr_to_null,
1040 gboolean child_inherits_stdin,
1041 gboolean file_and_argv_zero,
1042 GSpawnChildSetupFunc child_setup,
1045 if (working_directory && chdir (working_directory) < 0)
1046 write_err_and_exit (child_err_report_fd,
1047 CHILD_CHDIR_FAILED);
1049 /* Close all file descriptors but stdin stdout and stderr as
1050 * soon as we exec. Note that this includes
1051 * child_err_report_fd, which keeps the parent from blocking
1052 * forever on the other end of that pipe.
1054 if (close_descriptors)
1056 fdwalk (set_cloexec, GINT_TO_POINTER(3));
1060 /* We need to do child_err_report_fd anyway */
1061 set_cloexec (GINT_TO_POINTER(0), child_err_report_fd);
1064 /* Redirect pipes as required */
1068 /* dup2 can't actually fail here I don't think */
1070 if (sane_dup2 (stdin_fd, 0) < 0)
1071 write_err_and_exit (child_err_report_fd,
1074 /* ignore this if it doesn't work */
1075 close_and_invalidate (&stdin_fd);
1077 else if (!child_inherits_stdin)
1079 /* Keep process from blocking on a read of stdin */
1080 gint read_null = open ("/dev/null", O_RDONLY);
1081 sane_dup2 (read_null, 0);
1082 close_and_invalidate (&read_null);
1087 /* dup2 can't actually fail here I don't think */
1089 if (sane_dup2 (stdout_fd, 1) < 0)
1090 write_err_and_exit (child_err_report_fd,
1093 /* ignore this if it doesn't work */
1094 close_and_invalidate (&stdout_fd);
1096 else if (stdout_to_null)
1098 gint write_null = sane_open ("/dev/null", O_WRONLY);
1099 sane_dup2 (write_null, 1);
1100 close_and_invalidate (&write_null);
1105 /* dup2 can't actually fail here I don't think */
1107 if (sane_dup2 (stderr_fd, 2) < 0)
1108 write_err_and_exit (child_err_report_fd,
1111 /* ignore this if it doesn't work */
1112 close_and_invalidate (&stderr_fd);
1114 else if (stderr_to_null)
1116 gint write_null = sane_open ("/dev/null", O_WRONLY);
1117 sane_dup2 (write_null, 2);
1118 close_and_invalidate (&write_null);
1121 /* Call user function just before we exec */
1124 (* child_setup) (user_data);
1128 file_and_argv_zero ? argv + 1 : argv,
1132 write_err_and_exit (child_err_report_fd,
1149 if (bytes >= sizeof(gint)*2)
1150 break; /* give up, who knows what happened, should not be
1156 ((gchar*)buf) + bytes,
1157 sizeof(gint) * n_ints_in_buf - bytes);
1158 if (chunk < 0 && errno == EINTR)
1165 /* Some weird shit happened, bail out */
1168 G_SPAWN_ERROR_FAILED,
1169 _("Failed to read from child pipe (%s)"),
1170 g_strerror (errsv));
1174 else if (chunk == 0)
1176 else /* chunk > 0 */
1180 *n_ints_read = (gint)(bytes / sizeof(gint));
1186 fork_exec_with_pipes (gboolean intermediate_child,
1187 const gchar *working_directory,
1190 gboolean close_descriptors,
1191 gboolean search_path,
1192 gboolean stdout_to_null,
1193 gboolean stderr_to_null,
1194 gboolean child_inherits_stdin,
1195 gboolean file_and_argv_zero,
1196 GSpawnChildSetupFunc child_setup,
1199 gint *standard_input,
1200 gint *standard_output,
1201 gint *standard_error,
1205 gint stdin_pipe[2] = { -1, -1 };
1206 gint stdout_pipe[2] = { -1, -1 };
1207 gint stderr_pipe[2] = { -1, -1 };
1208 gint child_err_report_pipe[2] = { -1, -1 };
1209 gint child_pid_report_pipe[2] = { -1, -1 };
1212 if (!make_pipe (child_err_report_pipe, error))
1215 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1216 goto cleanup_and_fail;
1218 if (standard_input && !make_pipe (stdin_pipe, error))
1219 goto cleanup_and_fail;
1221 if (standard_output && !make_pipe (stdout_pipe, error))
1222 goto cleanup_and_fail;
1224 if (standard_error && !make_pipe (stderr_pipe, error))
1225 goto cleanup_and_fail;
1236 _("Failed to fork (%s)"),
1237 g_strerror (errsv));
1239 goto cleanup_and_fail;
1243 /* Immediate child. This may or may not be the child that
1244 * actually execs the new process.
1247 /* Reset some signal handlers that we may use */
1248 signal (SIGCHLD, SIG_DFL);
1249 signal (SIGINT, SIG_DFL);
1250 signal (SIGTERM, SIG_DFL);
1251 signal (SIGHUP, SIG_DFL);
1253 /* Be sure we crash if the parent exits
1254 * and we write to the err_report_pipe
1256 signal (SIGPIPE, SIG_DFL);
1258 /* Close the parent's end of the pipes;
1259 * not needed in the close_descriptors case,
1262 close_and_invalidate (&child_err_report_pipe[0]);
1263 close_and_invalidate (&child_pid_report_pipe[0]);
1264 close_and_invalidate (&stdin_pipe[1]);
1265 close_and_invalidate (&stdout_pipe[0]);
1266 close_and_invalidate (&stderr_pipe[0]);
1268 if (intermediate_child)
1270 /* We need to fork an intermediate child that launches the
1271 * final child. The purpose of the intermediate child
1272 * is to exit, so we can waitpid() it immediately.
1273 * Then the grandchild will not become a zombie.
1275 GPid grandchild_pid;
1277 grandchild_pid = fork ();
1279 if (grandchild_pid < 0)
1281 /* report -1 as child PID */
1282 write_all (child_pid_report_pipe[1], &grandchild_pid,
1283 sizeof(grandchild_pid));
1285 write_err_and_exit (child_err_report_pipe[1],
1288 else if (grandchild_pid == 0)
1290 do_exec (child_err_report_pipe[1],
1301 child_inherits_stdin,
1308 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1309 close_and_invalidate (&child_pid_report_pipe[1]);
1316 /* Just run the child.
1319 do_exec (child_err_report_pipe[1],
1330 child_inherits_stdin,
1343 /* Close the uncared-about ends of the pipes */
1344 close_and_invalidate (&child_err_report_pipe[1]);
1345 close_and_invalidate (&child_pid_report_pipe[1]);
1346 close_and_invalidate (&stdin_pipe[0]);
1347 close_and_invalidate (&stdout_pipe[1]);
1348 close_and_invalidate (&stderr_pipe[1]);
1350 /* If we had an intermediate child, reap it */
1351 if (intermediate_child)
1354 if (waitpid (pid, &status, 0) < 0)
1358 else if (errno == ECHILD)
1359 ; /* do nothing, child already reaped */
1361 g_warning ("waitpid() should not fail in "
1362 "'fork_exec_with_pipes'");
1367 if (!read_ints (child_err_report_pipe[0],
1370 goto cleanup_and_fail;
1374 /* Error from the child. */
1378 case CHILD_CHDIR_FAILED:
1381 G_SPAWN_ERROR_CHDIR,
1382 _("Failed to change to directory '%s' (%s)"),
1384 g_strerror (buf[1]));
1388 case CHILD_EXEC_FAILED:
1391 exec_err_to_g_error (buf[1]),
1392 _("Failed to execute child process \"%s\" (%s)"),
1394 g_strerror (buf[1]));
1398 case CHILD_DUP2_FAILED:
1401 G_SPAWN_ERROR_FAILED,
1402 _("Failed to redirect output or input of child process (%s)"),
1403 g_strerror (buf[1]));
1407 case CHILD_FORK_FAILED:
1411 _("Failed to fork child process (%s)"),
1412 g_strerror (buf[1]));
1418 G_SPAWN_ERROR_FAILED,
1419 _("Unknown error executing child process \"%s\""),
1424 goto cleanup_and_fail;
1427 /* Get child pid from intermediate child pipe. */
1428 if (intermediate_child)
1432 if (!read_ints (child_pid_report_pipe[0],
1433 buf, 1, &n_ints, error))
1434 goto cleanup_and_fail;
1442 G_SPAWN_ERROR_FAILED,
1443 _("Failed to read enough data from child pid pipe (%s)"),
1444 g_strerror (errsv));
1445 goto cleanup_and_fail;
1449 /* we have the child pid */
1454 /* Success against all odds! return the information */
1455 close_and_invalidate (&child_err_report_pipe[0]);
1456 close_and_invalidate (&child_pid_report_pipe[0]);
1462 *standard_input = stdin_pipe[1];
1463 if (standard_output)
1464 *standard_output = stdout_pipe[0];
1466 *standard_error = stderr_pipe[0];
1473 /* There was an error from the Child, reap the child to avoid it being
1480 if (waitpid (pid, NULL, 0) < 0)
1484 else if (errno == ECHILD)
1485 ; /* do nothing, child already reaped */
1487 g_warning ("waitpid() should not fail in "
1488 "'fork_exec_with_pipes'");
1492 close_and_invalidate (&child_err_report_pipe[0]);
1493 close_and_invalidate (&child_err_report_pipe[1]);
1494 close_and_invalidate (&child_pid_report_pipe[0]);
1495 close_and_invalidate (&child_pid_report_pipe[1]);
1496 close_and_invalidate (&stdin_pipe[0]);
1497 close_and_invalidate (&stdin_pipe[1]);
1498 close_and_invalidate (&stdout_pipe[0]);
1499 close_and_invalidate (&stdout_pipe[1]);
1500 close_and_invalidate (&stderr_pipe[0]);
1501 close_and_invalidate (&stderr_pipe[1]);
1507 make_pipe (gint p[2],
1515 G_SPAWN_ERROR_FAILED,
1516 _("Failed to create pipe for communicating with child process (%s)"),
1517 g_strerror (errsv));
1524 /* Based on execvp from GNU C Library */
1527 script_execute (const gchar *file,
1530 gboolean search_path)
1532 /* Count the arguments. */
1537 /* Construct an argument list for the shell. */
1541 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1543 new_argv[0] = (char *) "/bin/sh";
1544 new_argv[1] = (char *) file;
1547 new_argv[argc + 1] = argv[argc];
1551 /* Execute the shell. */
1553 execve (new_argv[0], new_argv, envp);
1555 execv (new_argv[0], new_argv);
1562 my_strchrnul (const gchar *str, gchar c)
1564 gchar *p = (gchar*) str;
1565 while (*p && (*p != c))
1572 g_execute (const gchar *file,
1575 gboolean search_path)
1579 /* We check the simple case first. */
1584 if (!search_path || strchr (file, '/') != NULL)
1586 /* Don't search when it contains a slash. */
1588 execve (file, argv, envp);
1592 if (errno == ENOEXEC)
1593 script_execute (file, argv, envp, FALSE);
1597 gboolean got_eacces = 0;
1598 const gchar *path, *p;
1599 gchar *name, *freeme;
1603 path = g_getenv ("PATH");
1606 /* There is no `PATH' in the environment. The default
1607 * search path in libc is the current directory followed by
1608 * the path `confstr' returns for `_CS_PATH'.
1611 /* In GLib we put . last, for security, and don't use the
1612 * unportable confstr(); UNIX98 does not actually specify
1613 * what to search if PATH is unset. POSIX may, dunno.
1616 path = "/bin:/usr/bin:.";
1619 len = strlen (file) + 1;
1620 pathlen = strlen (path);
1621 freeme = name = g_malloc (pathlen + len + 1);
1623 /* Copy the file name at the top, including '\0' */
1624 memcpy (name + pathlen + 1, file, len);
1625 name = name + pathlen;
1626 /* And add the slash before the filename */
1635 p = my_strchrnul (path, ':');
1638 /* Two adjacent colons, or a colon at the beginning or the end
1639 * of `PATH' means to search the current directory.
1643 startp = memcpy (name - (p - path), path, p - path);
1645 /* Try to execute this name. If it works, execv will not return. */
1647 execve (startp, argv, envp);
1649 execv (startp, argv);
1651 if (errno == ENOEXEC)
1652 script_execute (startp, argv, envp, search_path);
1657 /* Record the we got a `Permission denied' error. If we end
1658 * up finding no executable we can use, we want to diagnose
1659 * that we did find one but were denied access.
1672 /* Those errors indicate the file is missing or not executable
1673 * by us, in which case we want to just try the next path
1679 /* Some other error means we found an executable file, but
1680 * something went wrong executing it; return the error to our
1687 while (*p++ != '\0');
1689 /* We tried every element and none of them worked. */
1691 /* At least one failure was due to permissions, so report that
1699 /* Return the error from the last attempt (probably ENOENT). */
1704 * g_spawn_close_pid:
1705 * @pid: The process reference to close
1707 * On some platforms, notably Windows, the #GPid type represents a resource
1708 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1709 * is provided for this purpose. It should be used on all platforms, even
1710 * though it doesn't do anything under UNIX.
1713 g_spawn_close_pid (GPid pid)