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 */
35 #ifdef HAVE_SYS_SELECT_H
36 #include <sys/select.h>
37 #endif /* HAVE_SYS_SELECT_H */
43 static gint g_execute (const gchar *file,
46 gboolean search_path);
48 static gboolean make_pipe (gint p[2],
50 static gboolean fork_exec_with_pipes (gboolean intermediate_child,
51 const gchar *working_directory,
54 gboolean close_descriptors,
56 gboolean stdout_to_null,
57 gboolean stderr_to_null,
58 gboolean child_inherits_stdin,
59 gboolean file_and_argv_zero,
60 GSpawnChildSetupFunc child_setup,
64 gint *standard_output,
69 g_spawn_error_quark (void)
71 return g_quark_from_static_string ("g-exec-error-quark");
76 * @working_directory: child's current working directory, or %NULL to inherit parent's
77 * @argv: child's argument vector
78 * @envp: child's environment, or %NULL to inherit parent's
79 * @flags: flags from #GSpawnFlags
80 * @child_setup: function to run in the child just before exec()
81 * @user_data: user data for @child_setup
82 * @child_pid: return location for child process ID, or %NULL
83 * @error: return location for error
85 * See g_spawn_async_with_pipes() for a full description; this function
86 * simply calls the g_spawn_async_with_pipes() without any pipes.
88 * Return value: %TRUE on success, %FALSE if error is set
91 g_spawn_async (const gchar *working_directory,
95 GSpawnChildSetupFunc child_setup,
100 g_return_val_if_fail (argv != NULL, FALSE);
102 return g_spawn_async_with_pipes (working_directory,
112 /* Avoids a danger in threaded situations (calling close()
113 * on a file descriptor twice, and another thread has
114 * re-opened it since the first close)
117 close_and_invalidate (gint *fd)
136 READ_FAILED = 0, /* FALSE */
142 read_data (GString *str,
151 bytes = read (fd, buf, 4096);
157 g_string_append_len (str, buf, bytes);
160 else if (bytes < 0 && errno == EINTR)
167 _("Failed to read data from child process (%s)"),
178 * @working_directory: child's current working directory, or %NULL to inherit parent's
179 * @argv: child's argument vector
180 * @envp: child's environment, or %NULL to inherit parent's
181 * @flags: flags from #GSpawnFlags
182 * @child_setup: function to run in the child just before exec()
183 * @user_data: user data for @child_setup
184 * @standard_output: return location for child output
185 * @standard_error: return location for child error messages
186 * @exit_status: return location for child exit status, as returned by waitpid()
187 * @error: return location for error
189 * Executes a child synchronously (waits for the child to exit before returning).
190 * All output from the child is stored in @standard_output and @standard_error,
191 * if those parameters are non-%NULL. If @exit_status is non-%NULL, the exit
192 * status of the child is stored there as it would be returned by
193 * waitpid(); standard UNIX macros such as WIFEXITED() and WEXITSTATUS()
194 * must be used to evaluate the exit status. If an error occurs, no data is
195 * returned in @standard_output, @standard_error, or @exit_status.
197 * This function calls g_spawn_async_with_pipes() internally; see that
198 * function for full details on the other parameters and details on
199 * how these functions work on Windows.
201 * Return value: %TRUE on success, %FALSE if an error was set.
204 g_spawn_sync (const gchar *working_directory,
208 GSpawnChildSetupFunc child_setup,
210 gchar **standard_output,
211 gchar **standard_error,
220 GString *outstr = NULL;
221 GString *errstr = NULL;
225 g_return_val_if_fail (argv != NULL, FALSE);
226 g_return_val_if_fail (!(flags & G_SPAWN_DO_NOT_REAP_CHILD), FALSE);
227 g_return_val_if_fail (standard_output == NULL ||
228 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
229 g_return_val_if_fail (standard_error == NULL ||
230 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
232 /* Just to ensure segfaults if callers try to use
233 * these when an error is reported.
236 *standard_output = NULL;
239 *standard_error = NULL;
241 if (!fork_exec_with_pipes (FALSE,
245 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
246 (flags & G_SPAWN_SEARCH_PATH) != 0,
247 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
248 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
249 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
250 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
255 standard_output ? &outpipe : NULL,
256 standard_error ? &errpipe : NULL,
260 /* Read data from child. */
266 outstr = g_string_new (NULL);
271 errstr = g_string_new (NULL);
274 /* Read data until we get EOF on both pipes. */
283 FD_SET (outpipe, &fds);
285 FD_SET (errpipe, &fds);
287 ret = select (MAX (outpipe, errpipe) + 1,
290 NULL /* no timeout */);
292 if (ret < 0 && errno != EINTR)
299 _("Unexpected error in select() reading data from a child process (%s)"),
305 if (outpipe >= 0 && FD_ISSET (outpipe, &fds))
307 switch (read_data (outstr, outpipe, error))
313 close_and_invalidate (&outpipe);
324 if (errpipe >= 0 && FD_ISSET (errpipe, &fds))
326 switch (read_data (errstr, errpipe, error))
332 close_and_invalidate (&errpipe);
344 /* These should only be open still if we had an error. */
347 close_and_invalidate (&outpipe);
349 close_and_invalidate (&errpipe);
351 /* Wait for child to exit, even if we have
356 ret = waitpid (pid, &status, 0);
362 else if (errno == ECHILD)
366 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.");
370 /* We don't need the exit status. */
375 if (!failed) /* avoid error pileups */
382 _("Unexpected error in waitpid() (%s)"),
391 g_string_free (outstr, TRUE);
393 g_string_free (errstr, TRUE);
400 *exit_status = status;
403 *standard_output = g_string_free (outstr, FALSE);
406 *standard_error = g_string_free (errstr, FALSE);
413 * g_spawn_async_with_pipes:
414 * @working_directory: child's current working directory, or %NULL to inherit parent's, in the GLib file name encoding
415 * @argv: child's argument vector, in the GLib file name encoding
416 * @envp: child's environment, or %NULL to inherit parent's, in the GLib file name encoding
417 * @flags: flags from #GSpawnFlags
418 * @child_setup: function to run in the child just before exec()
419 * @user_data: user data for @child_setup
420 * @child_pid: return location for child process ID, or %NULL
421 * @standard_input: return location for file descriptor to write to child's stdin, or %NULL
422 * @standard_output: return location for file descriptor to read child's stdout, or %NULL
423 * @standard_error: return location for file descriptor to read child's stderr, or %NULL
424 * @error: return location for error
426 * Executes a child program asynchronously (your program will not
427 * block waiting for the child to exit). The child program is
428 * specified by the only argument that must be provided, @argv. @argv
429 * should be a %NULL-terminated array of strings, to be passed as the
430 * argument vector for the child. The first string in @argv is of
431 * course the name of the program to execute. By default, the name of
432 * the program must be a full path; the <envar>PATH</envar> shell variable
433 * will only be searched if you pass the %G_SPAWN_SEARCH_PATH flag.
435 * On Windows, note that all the string or string vector arguments to
436 * this function and the other g_spawn*() functions are in UTF-8, the
437 * GLib file name encoding. Unicode characters that are not part of
438 * the system codepage passed in argument vectors will be correctly
439 * available in the spawned program only if it uses wide character API
440 * to retrieve its command line. For C programs built with Microsoft's
441 * tools it is enough to make the program have a wmain() instead of
442 * main(). wmain() has a wide character argument vector as parameter.
444 * At least currently, mingw doesn't support wmain(), so if you use
445 * mingw to develop the spawned program, it will have to call the
446 * undocumented function __wgetmainargs() to get the wide character
447 * argument vector and environment. See gspawn-win32-helper.c in the
448 * GLib sources or init.c in the mingw runtime sources for a prototype
449 * for that function. Alternatively, you can retrieve the Win32 system
450 * level wide character command line passed to the spawned program
451 * using the GetCommandLineW() function.
453 * On Windows the low-level child process creation API
454 * <function>CreateProcess()</function> doesn't use argument vectors,
455 * but a command line. The C runtime library's
456 * <function>spawn*()</function> family of functions (which
457 * g_spawn_async_with_pipes() eventually calls) paste the argument
458 * vector elements together into a command line, and the C runtime startup code
459 * does a corresponding reconstruction of an argument vector from the
460 * command line, to be passed to main(). Complications arise when you have
461 * argument vector elements that contain spaces of double quotes. The
462 * <function>spawn*()</function> functions don't do any quoting or
463 * escaping, but on the other hand the startup code does do unquoting
464 * and unescaping in order to enable receiving arguments with embedded
465 * spaces or double quotes. To work around this asymmetry,
466 * g_spawn_async_with_pipes() will do quoting and escaping on argument
467 * vector elements that need it before calling the C runtime
470 * @envp is a %NULL-terminated array of strings, where each string
471 * has the form <literal>KEY=VALUE</literal>. This will become
472 * the child's environment. If @envp is %NULL, the child inherits its
473 * parent's environment.
475 * @flags should be the bitwise OR of any flags you want to affect the
476 * function's behaviour. The %G_SPAWN_DO_NOT_REAP_CHILD means that
477 * the child will not automatically be reaped; you must use a
478 * #GChildWatch source to be notified about the death of the child
479 * process. Eventually you must call g_spawn_close_pid() on the
480 * @child_pid, in order to free resources which may be associated
481 * with the child process. (On Unix, using a #GChildWatch source is
482 * equivalent to calling waitpid() or handling the %SIGCHLD signal
483 * manually. On Windows, calling g_spawn_close_pid() is equivalent
484 * to calling CloseHandle() on the process handle returned in
487 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
488 * descriptors will be inherited by the child; otherwise all
489 * descriptors except stdin/stdout/stderr will be closed before
490 * calling exec() in the child. %G_SPAWN_SEARCH_PATH
491 * means that <literal>argv[0]</literal> need not be an absolute path, it
492 * will be looked for in the user's <envar>PATH</envar>.
493 * %G_SPAWN_STDOUT_TO_DEV_NULL means that the child's standard output will
494 * be discarded, instead of going to the same location as the parent's
495 * standard output. If you use this flag, @standard_output must be %NULL.
496 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
497 * will be discarded, instead of going to the same location as the parent's
498 * standard error. If you use this flag, @standard_error must be %NULL.
499 * %G_SPAWN_CHILD_INHERITS_STDIN means that the child will inherit the parent's
500 * standard input (by default, the child's standard input is attached to
501 * /dev/null). If you use this flag, @standard_input must be %NULL.
502 * %G_SPAWN_FILE_AND_ARGV_ZERO means that the first element of @argv is
503 * the file to execute, while the remaining elements are the
504 * actual argument vector to pass to the file. Normally
505 * g_spawn_async_with_pipes() uses @argv[0] as the file to execute, and
506 * passes all of @argv to the child.
508 * @child_setup and @user_data are a function and user data. On POSIX
509 * platforms, the function is called in the child after GLib has
510 * performed all the setup it plans to perform (including creating
511 * pipes, closing file descriptors, etc.) but before calling
512 * exec(). That is, @child_setup is called just
513 * before calling exec() in the child. Obviously
514 * actions taken in this function will only affect the child, not the
515 * parent. On Windows, there is no separate fork() and exec()
516 * functionality. Child processes are created and run with
517 * a single API call, CreateProcess(). @child_setup is
518 * called in the parent process just before creating the child
519 * process. You should carefully consider what you do in @child_setup
520 * if you intend your software to be portable to Windows.
522 * If non-%NULL, @child_pid will on Unix be filled with the child's
523 * process ID. You can use the process ID to send signals to the
524 * child, or to waitpid() if you specified the
525 * %G_SPAWN_DO_NOT_REAP_CHILD flag. On Windows, @child_pid will be
526 * filled with a handle to the child process only if you specified the
527 * %G_SPAWN_DO_NOT_REAP_CHILD flag. You can then access the child
528 * process using the Win32 API, for example wait for its termination
529 * with the <function>WaitFor*()</function> functions, or examine its
530 * exit code with GetExitCodeProcess(). You should close the handle
531 * with CloseHandle() or g_spawn_close_pid() when you no longer need it.
533 * If non-%NULL, the @standard_input, @standard_output, @standard_error
534 * locations will be filled with file descriptors for writing to the child's
535 * standard input or reading from its standard output or standard error.
536 * The caller of g_spawn_async_with_pipes() must close these file descriptors
537 * when they are no longer in use. If these parameters are %NULL, the corresponding
538 * pipe won't be created.
540 * If @standard_input is NULL, the child's standard input is attached to /dev/null
541 * unless %G_SPAWN_CHILD_INHERITS_STDIN is set.
543 * If @standard_error is NULL, the child's standard error goes to the same location
544 * as the parent's standard error unless %G_SPAWN_STDERR_TO_DEV_NULL is set.
546 * If @standard_output is NULL, the child's standard output goes to the same location
547 * as the parent's standard output unless %G_SPAWN_STDOUT_TO_DEV_NULL is set.
549 * @error can be %NULL to ignore errors, or non-%NULL to report errors.
550 * If an error is set, the function returns %FALSE. Errors
551 * are reported even if they occur in the child (for example if the
552 * executable in <literal>argv[0]</literal> is not found). Typically
553 * the <literal>message</literal> field of returned errors should be displayed
554 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
556 * If an error occurs, @child_pid, @standard_input, @standard_output,
557 * and @standard_error will not be filled with valid values.
559 * If @child_pid is not %NULL and an error does not occur then the returned
560 * pid must be closed using g_spawn_close_pid().
562 * Return value: %TRUE on success, %FALSE if an error was set
565 g_spawn_async_with_pipes (const gchar *working_directory,
569 GSpawnChildSetupFunc child_setup,
572 gint *standard_input,
573 gint *standard_output,
574 gint *standard_error,
577 g_return_val_if_fail (argv != NULL, FALSE);
578 g_return_val_if_fail (standard_output == NULL ||
579 !(flags & G_SPAWN_STDOUT_TO_DEV_NULL), FALSE);
580 g_return_val_if_fail (standard_error == NULL ||
581 !(flags & G_SPAWN_STDERR_TO_DEV_NULL), FALSE);
582 /* can't inherit stdin if we have an input pipe. */
583 g_return_val_if_fail (standard_input == NULL ||
584 !(flags & G_SPAWN_CHILD_INHERITS_STDIN), FALSE);
586 return fork_exec_with_pipes (!(flags & G_SPAWN_DO_NOT_REAP_CHILD),
590 !(flags & G_SPAWN_LEAVE_DESCRIPTORS_OPEN),
591 (flags & G_SPAWN_SEARCH_PATH) != 0,
592 (flags & G_SPAWN_STDOUT_TO_DEV_NULL) != 0,
593 (flags & G_SPAWN_STDERR_TO_DEV_NULL) != 0,
594 (flags & G_SPAWN_CHILD_INHERITS_STDIN) != 0,
595 (flags & G_SPAWN_FILE_AND_ARGV_ZERO) != 0,
606 * g_spawn_command_line_sync:
607 * @command_line: a command line
608 * @standard_output: return location for child output
609 * @standard_error: return location for child errors
610 * @exit_status: return location for child exit status, as returned by waitpid()
611 * @error: return location for errors
613 * A simple version of g_spawn_sync() with little-used parameters
614 * removed, taking a command line instead of an argument vector. See
615 * g_spawn_sync() for full details. @command_line will be parsed by
616 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
617 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
618 * implications, so consider using g_spawn_sync() directly if
619 * appropriate. Possible errors are those from g_spawn_sync() and those
620 * from g_shell_parse_argv().
622 * If @exit_status is non-%NULL, the exit status of the child is stored there as
623 * it would be returned by waitpid(); standard UNIX macros such as WIFEXITED()
624 * and WEXITSTATUS() must be used to evaluate the exit status.
626 * On Windows, please note the implications of g_shell_parse_argv()
627 * parsing @command_line. Parsing is done according to Unix shell rules, not
628 * Windows command interpreter rules.
629 * Space is a separator, and backslashes are
630 * special. Thus you cannot simply pass a @command_line containing
631 * canonical Windows paths, like "c:\\program files\\app\\app.exe", as
632 * the backslashes will be eaten, and the space will act as a
633 * separator. You need to enclose such paths with single quotes, like
634 * "'c:\\program files\\app\\app.exe' 'e:\\folder\\argument.txt'".
636 * Return value: %TRUE on success, %FALSE if an error was set
639 g_spawn_command_line_sync (const gchar *command_line,
640 gchar **standard_output,
641 gchar **standard_error,
648 g_return_val_if_fail (command_line != NULL, FALSE);
650 if (!g_shell_parse_argv (command_line,
655 retval = g_spawn_sync (NULL,
671 * g_spawn_command_line_async:
672 * @command_line: a command line
673 * @error: return location for errors
675 * A simple version of g_spawn_async() that parses a command line with
676 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
677 * command line in the background. Unlike g_spawn_async(), the
678 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
679 * that %G_SPAWN_SEARCH_PATH can have security implications, so
680 * consider using g_spawn_async() directly if appropriate. Possible
681 * errors are those from g_shell_parse_argv() and g_spawn_async().
683 * The same concerns on Windows apply as for g_spawn_command_line_sync().
685 * Return value: %TRUE on success, %FALSE if error is set.
688 g_spawn_command_line_async (const gchar *command_line,
694 g_return_val_if_fail (command_line != NULL, FALSE);
696 if (!g_shell_parse_argv (command_line,
701 retval = g_spawn_async (NULL,
715 exec_err_to_g_error (gint en)
721 return G_SPAWN_ERROR_ACCES;
727 return G_SPAWN_ERROR_PERM;
733 return G_SPAWN_ERROR_2BIG;
739 return G_SPAWN_ERROR_NOEXEC;
745 return G_SPAWN_ERROR_NAMETOOLONG;
751 return G_SPAWN_ERROR_NOENT;
757 return G_SPAWN_ERROR_NOMEM;
763 return G_SPAWN_ERROR_NOTDIR;
769 return G_SPAWN_ERROR_LOOP;
775 return G_SPAWN_ERROR_TXTBUSY;
781 return G_SPAWN_ERROR_IO;
787 return G_SPAWN_ERROR_NFILE;
793 return G_SPAWN_ERROR_MFILE;
799 return G_SPAWN_ERROR_INVAL;
805 return G_SPAWN_ERROR_ISDIR;
811 return G_SPAWN_ERROR_LIBBAD;
816 return G_SPAWN_ERROR_FAILED;
822 write_all (gint fd, gconstpointer vbuf, gsize to_write)
824 gchar *buf = (gchar *) vbuf;
828 gssize count = write (fd, buf, to_write);
845 write_err_and_exit (gint fd, gint msg)
849 write_all (fd, &msg, sizeof(msg));
850 write_all (fd, &en, sizeof(en));
856 set_cloexec (void *data, gint fd)
859 fcntl (fd, F_SETFD, FD_CLOEXEC);
864 fdwalk (int (*cb)(void *data, int fd), void *data)
871 open_max = sysconf (_SC_OPEN_MAX);
872 for (fd = 0; fd < open_max && res == 0; fd++)
880 sane_dup2 (gint fd1, gint fd2)
885 ret = dup2 (fd1, fd2);
886 if (ret < 0 && errno == EINTR)
901 do_exec (gint child_err_report_fd,
905 const gchar *working_directory,
908 gboolean close_descriptors,
909 gboolean search_path,
910 gboolean stdout_to_null,
911 gboolean stderr_to_null,
912 gboolean child_inherits_stdin,
913 gboolean file_and_argv_zero,
914 GSpawnChildSetupFunc child_setup,
917 if (working_directory && chdir (working_directory) < 0)
918 write_err_and_exit (child_err_report_fd,
921 /* Close all file descriptors but stdin stdout and stderr as
922 * soon as we exec. Note that this includes
923 * child_err_report_fd, which keeps the parent from blocking
924 * forever on the other end of that pipe.
926 if (close_descriptors)
928 fdwalk (set_cloexec, NULL);
932 /* We need to do child_err_report_fd anyway */
933 set_cloexec (NULL, child_err_report_fd);
936 /* Redirect pipes as required */
940 /* dup2 can't actually fail here I don't think */
942 if (sane_dup2 (stdin_fd, 0) < 0)
943 write_err_and_exit (child_err_report_fd,
946 /* ignore this if it doesn't work */
947 close_and_invalidate (&stdin_fd);
949 else if (!child_inherits_stdin)
951 /* Keep process from blocking on a read of stdin */
952 gint read_null = open ("/dev/null", O_RDONLY);
953 sane_dup2 (read_null, 0);
954 close_and_invalidate (&read_null);
959 /* dup2 can't actually fail here I don't think */
961 if (sane_dup2 (stdout_fd, 1) < 0)
962 write_err_and_exit (child_err_report_fd,
965 /* ignore this if it doesn't work */
966 close_and_invalidate (&stdout_fd);
968 else if (stdout_to_null)
970 gint write_null = open ("/dev/null", O_WRONLY);
971 sane_dup2 (write_null, 1);
972 close_and_invalidate (&write_null);
977 /* dup2 can't actually fail here I don't think */
979 if (sane_dup2 (stderr_fd, 2) < 0)
980 write_err_and_exit (child_err_report_fd,
983 /* ignore this if it doesn't work */
984 close_and_invalidate (&stderr_fd);
986 else if (stderr_to_null)
988 gint write_null = open ("/dev/null", O_WRONLY);
989 sane_dup2 (write_null, 2);
990 close_and_invalidate (&write_null);
993 /* Call user function just before we exec */
996 (* child_setup) (user_data);
1000 file_and_argv_zero ? argv + 1 : argv,
1004 write_err_and_exit (child_err_report_fd,
1021 if (bytes >= sizeof(gint)*2)
1022 break; /* give up, who knows what happened, should not be
1028 ((gchar*)buf) + bytes,
1029 sizeof(gint) * n_ints_in_buf - bytes);
1030 if (chunk < 0 && errno == EINTR)
1035 /* Some weird shit happened, bail out */
1039 G_SPAWN_ERROR_FAILED,
1040 _("Failed to read from child pipe (%s)"),
1041 g_strerror (errno));
1045 else if (chunk == 0)
1047 else /* chunk > 0 */
1051 *n_ints_read = (gint)(bytes / sizeof(gint));
1057 fork_exec_with_pipes (gboolean intermediate_child,
1058 const gchar *working_directory,
1061 gboolean close_descriptors,
1062 gboolean search_path,
1063 gboolean stdout_to_null,
1064 gboolean stderr_to_null,
1065 gboolean child_inherits_stdin,
1066 gboolean file_and_argv_zero,
1067 GSpawnChildSetupFunc child_setup,
1070 gint *standard_input,
1071 gint *standard_output,
1072 gint *standard_error,
1076 gint stdin_pipe[2] = { -1, -1 };
1077 gint stdout_pipe[2] = { -1, -1 };
1078 gint stderr_pipe[2] = { -1, -1 };
1079 gint child_err_report_pipe[2] = { -1, -1 };
1080 gint child_pid_report_pipe[2] = { -1, -1 };
1083 if (!make_pipe (child_err_report_pipe, error))
1086 if (intermediate_child && !make_pipe (child_pid_report_pipe, error))
1087 goto cleanup_and_fail;
1089 if (standard_input && !make_pipe (stdin_pipe, error))
1090 goto cleanup_and_fail;
1092 if (standard_output && !make_pipe (stdout_pipe, error))
1093 goto cleanup_and_fail;
1095 if (standard_error && !make_pipe (stderr_pipe, error))
1096 goto cleanup_and_fail;
1105 _("Failed to fork (%s)"),
1106 g_strerror (errno));
1108 goto cleanup_and_fail;
1112 /* Immediate child. This may or may not be the child that
1113 * actually execs the new process.
1116 /* Be sure we crash if the parent exits
1117 * and we write to the err_report_pipe
1119 signal (SIGPIPE, SIG_DFL);
1121 /* Close the parent's end of the pipes;
1122 * not needed in the close_descriptors case,
1125 close_and_invalidate (&child_err_report_pipe[0]);
1126 close_and_invalidate (&child_pid_report_pipe[0]);
1127 close_and_invalidate (&stdin_pipe[1]);
1128 close_and_invalidate (&stdout_pipe[0]);
1129 close_and_invalidate (&stderr_pipe[0]);
1131 if (intermediate_child)
1133 /* We need to fork an intermediate child that launches the
1134 * final child. The purpose of the intermediate child
1135 * is to exit, so we can waitpid() it immediately.
1136 * Then the grandchild will not become a zombie.
1138 GPid grandchild_pid;
1140 grandchild_pid = fork ();
1142 if (grandchild_pid < 0)
1144 /* report -1 as child PID */
1145 write_all (child_pid_report_pipe[1], &grandchild_pid,
1146 sizeof(grandchild_pid));
1148 write_err_and_exit (child_err_report_pipe[1],
1151 else if (grandchild_pid == 0)
1153 do_exec (child_err_report_pipe[1],
1164 child_inherits_stdin,
1171 write_all (child_pid_report_pipe[1], &grandchild_pid, sizeof(grandchild_pid));
1172 close_and_invalidate (&child_pid_report_pipe[1]);
1179 /* Just run the child.
1182 do_exec (child_err_report_pipe[1],
1193 child_inherits_stdin,
1206 /* Close the uncared-about ends of the pipes */
1207 close_and_invalidate (&child_err_report_pipe[1]);
1208 close_and_invalidate (&child_pid_report_pipe[1]);
1209 close_and_invalidate (&stdin_pipe[0]);
1210 close_and_invalidate (&stdout_pipe[1]);
1211 close_and_invalidate (&stderr_pipe[1]);
1213 /* If we had an intermediate child, reap it */
1214 if (intermediate_child)
1217 if (waitpid (pid, &status, 0) < 0)
1221 else if (errno == ECHILD)
1222 ; /* do nothing, child already reaped */
1224 g_warning ("waitpid() should not fail in "
1225 "'fork_exec_with_pipes'");
1230 if (!read_ints (child_err_report_pipe[0],
1233 goto cleanup_and_fail;
1237 /* Error from the child. */
1241 case CHILD_CHDIR_FAILED:
1244 G_SPAWN_ERROR_CHDIR,
1245 _("Failed to change to directory '%s' (%s)"),
1247 g_strerror (buf[1]));
1251 case CHILD_EXEC_FAILED:
1254 exec_err_to_g_error (buf[1]),
1255 _("Failed to execute child process \"%s\" (%s)"),
1257 g_strerror (buf[1]));
1261 case CHILD_DUP2_FAILED:
1264 G_SPAWN_ERROR_FAILED,
1265 _("Failed to redirect output or input of child process (%s)"),
1266 g_strerror (buf[1]));
1270 case CHILD_FORK_FAILED:
1274 _("Failed to fork child process (%s)"),
1275 g_strerror (buf[1]));
1281 G_SPAWN_ERROR_FAILED,
1282 _("Unknown error executing child process \"%s\""),
1287 goto cleanup_and_fail;
1290 /* Get child pid from intermediate child pipe. */
1291 if (intermediate_child)
1295 if (!read_ints (child_pid_report_pipe[0],
1296 buf, 1, &n_ints, error))
1297 goto cleanup_and_fail;
1303 G_SPAWN_ERROR_FAILED,
1304 _("Failed to read enough data from child pid pipe (%s)"),
1305 g_strerror (errno));
1306 goto cleanup_and_fail;
1310 /* we have the child pid */
1315 /* Success against all odds! return the information */
1316 close_and_invalidate (&child_err_report_pipe[0]);
1317 close_and_invalidate (&child_pid_report_pipe[0]);
1323 *standard_input = stdin_pipe[1];
1324 if (standard_output)
1325 *standard_output = stdout_pipe[0];
1327 *standard_error = stderr_pipe[0];
1334 /* There was an error from the Child, reap the child to avoid it being
1341 if (waitpid (pid, NULL, 0) < 0)
1345 else if (errno == ECHILD)
1346 ; /* do nothing, child already reaped */
1348 g_warning ("waitpid() should not fail in "
1349 "'fork_exec_with_pipes'");
1353 close_and_invalidate (&child_err_report_pipe[0]);
1354 close_and_invalidate (&child_err_report_pipe[1]);
1355 close_and_invalidate (&child_pid_report_pipe[0]);
1356 close_and_invalidate (&child_pid_report_pipe[1]);
1357 close_and_invalidate (&stdin_pipe[0]);
1358 close_and_invalidate (&stdin_pipe[1]);
1359 close_and_invalidate (&stdout_pipe[0]);
1360 close_and_invalidate (&stdout_pipe[1]);
1361 close_and_invalidate (&stderr_pipe[0]);
1362 close_and_invalidate (&stderr_pipe[1]);
1368 make_pipe (gint p[2],
1375 G_SPAWN_ERROR_FAILED,
1376 _("Failed to create pipe for communicating with child process (%s)"),
1377 g_strerror (errno));
1384 /* Based on execvp from GNU C Library */
1387 script_execute (const gchar *file,
1390 gboolean search_path)
1392 /* Count the arguments. */
1397 /* Construct an argument list for the shell. */
1401 new_argv = g_new0 (gchar*, argc + 2); /* /bin/sh and NULL */
1403 new_argv[0] = (char *) "/bin/sh";
1404 new_argv[1] = (char *) file;
1407 new_argv[argc + 1] = argv[argc];
1411 /* Execute the shell. */
1413 execve (new_argv[0], new_argv, envp);
1415 execv (new_argv[0], new_argv);
1422 my_strchrnul (const gchar *str, gchar c)
1424 gchar *p = (gchar*) str;
1425 while (*p && (*p != c))
1432 g_execute (const gchar *file,
1435 gboolean search_path)
1439 /* We check the simple case first. */
1444 if (!search_path || strchr (file, '/') != NULL)
1446 /* Don't search when it contains a slash. */
1448 execve (file, argv, envp);
1452 if (errno == ENOEXEC)
1453 script_execute (file, argv, envp, FALSE);
1457 gboolean got_eacces = 0;
1458 const gchar *path, *p;
1459 gchar *name, *freeme;
1463 path = g_getenv ("PATH");
1466 /* There is no `PATH' in the environment. The default
1467 * search path in libc is the current directory followed by
1468 * the path `confstr' returns for `_CS_PATH'.
1471 /* In GLib we put . last, for security, and don't use the
1472 * unportable confstr(); UNIX98 does not actually specify
1473 * what to search if PATH is unset. POSIX may, dunno.
1476 path = "/bin:/usr/bin:.";
1479 len = strlen (file) + 1;
1480 pathlen = strlen (path);
1481 freeme = name = g_malloc (pathlen + len + 1);
1483 /* Copy the file name at the top, including '\0' */
1484 memcpy (name + pathlen + 1, file, len);
1485 name = name + pathlen;
1486 /* And add the slash before the filename */
1495 p = my_strchrnul (path, ':');
1498 /* Two adjacent colons, or a colon at the beginning or the end
1499 * of `PATH' means to search the current directory.
1503 startp = memcpy (name - (p - path), path, p - path);
1505 /* Try to execute this name. If it works, execv will not return. */
1507 execve (startp, argv, envp);
1509 execv (startp, argv);
1511 if (errno == ENOEXEC)
1512 script_execute (startp, argv, envp, search_path);
1517 /* Record the we got a `Permission denied' error. If we end
1518 * up finding no executable we can use, we want to diagnose
1519 * that we did find one but were denied access.
1532 /* Those errors indicate the file is missing or not executable
1533 * by us, in which case we want to just try the next path
1539 /* Some other error means we found an executable file, but
1540 * something went wrong executing it; return the error to our
1547 while (*p++ != '\0');
1549 /* We tried every element and none of them worked. */
1551 /* At least one failure was due to permissions, so report that
1559 /* Return the error from the last attempt (probably ENOENT). */
1564 * g_spawn_close_pid:
1565 * @pid: The process identifier to close
1567 * On some platforms, notably WIN32, the #GPid type represents a resource
1568 * which must be closed to prevent resource leaking. g_spawn_close_pid()
1569 * is provided for this purpose. It should be used on all platforms, even
1570 * though it doesn't do anything under UNIX.
1573 g_spawn_close_pid (GPid pid)
1577 #define __G_SPAWN_C__
1578 #include "galiasdef.c"