1 /* gspawn-win32.c - Process launching on Win32
3 * Copyright 2000 Red Hat, Inc.
5 * GLib is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public License as
7 * published by the Free Software Foundation; either version 2 of the
8 * License, or (at your option) any later version.
10 * GLib is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with GLib; see the file COPYING.LIB. If not, write
17 * to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 * Boston, MA 02111-1307, USA.
22 * Implementation details on Win32.
24 * - There is no way to set the no-inherit flag for
25 * a "file descriptor" in the MS C runtime. The flag is there,
26 * and the dospawn() function uses it, but unfortunately
27 * this flag can only be set when opening the file.
28 * - As there is no fork(), we cannot reliably change directory
29 * before starting the child process. (There might be several threads
30 * running, and the current directory is common for all threads.)
32 * Thus, we must in most cases use a helper program to handle closing
33 * of (inherited) file descriptors and changing of directory. In fact,
34 * we do it all the time.
36 * This source file contains the source for that helper program.
37 * To compile it, #define GSPAWN_HELPER.
40 /* Define this to get some logging all the time */
41 /* #define G_SPAWN_WIN32_DEBUG */
58 #ifdef G_SPAWN_WIN32_DEBUG
60 #define SETUP_DEBUG() /* empty */
63 static int debug
= -1;
64 #define SETUP_DEBUG() \
69 if (getenv ("G_SPAWN_WIN32_DEBUG") != NULL) \
86 ARG_CHILD_ERR_REPORT
= 1,
90 ARG_WORKING_DIRECTORY
,
91 ARG_CLOSE_DESCRIPTORS
,
95 ARG_COUNT
= ARG_PROGRAM
100 static gboolean
make_pipe (gint p
[2],
102 static gboolean
fork_exec_with_pipes (gboolean dont_wait
,
103 const gchar
*working_directory
,
106 gboolean close_descriptors
,
107 gboolean search_path
,
108 gboolean stdout_to_null
,
109 gboolean stderr_to_null
,
110 gboolean child_inherits_stdin
,
111 GSpawnChildSetupFunc child_setup
,
113 gint
*standard_input
,
114 gint
*standard_output
,
115 gint
*standard_error
,
120 g_spawn_error_quark (void)
122 static GQuark quark
= 0;
124 quark
= g_quark_from_static_string ("g-exec-error-quark");
130 * @working_directory: child's current working directory, or NULL to inherit parent's
131 * @argv: child's argument vector
132 * @envp: child's environment, or NULL to inherit parent's
133 * @flags: flags from #GSpawnFlags
134 * @child_setup: function to run in the child just before exec()
135 * @user_data: user data for @child_setup
136 * @child_pid: return location for child process ID, or NULL
137 * @error: return location for error
139 * See g_spawn_async_with_pipes() for a full description; this function
140 * simply calls the g_spawn_async_with_pipes() without any pipes.
142 * Return value: TRUE on success, FALSE if error is set
145 g_spawn_async (const gchar
*working_directory
,
149 GSpawnChildSetupFunc child_setup
,
154 g_return_val_if_fail (argv
!= NULL
, FALSE
);
156 return g_spawn_async_with_pipes (working_directory
,
166 /* Avoids a danger in threaded situations (calling close()
167 * on a file descriptor twice, and another thread has
168 * re-opened it since the first close)
171 close_and_invalidate (gint
*fd
)
183 READ_FAILED
= 0, /* FALSE */
189 read_data (GString
*str
,
190 GIOChannel
*iochannel
,
199 gioerror
= g_io_channel_read (iochannel
, buf
, sizeof (buf
), &bytes
);
205 g_string_append_len (str
, buf
, bytes
);
208 else if (gioerror
== G_IO_ERROR_AGAIN
)
210 else if (gioerror
!= G_IO_ERROR_NONE
)
215 _("Failed to read data from child process"));
225 * @working_directory: child's current working directory, or NULL to inherit parent's
226 * @argv: child's argument vector
227 * @envp: child's environment, or NULL to inherit parent's
228 * @flags: flags from #GSpawnFlags
229 * @child_setup: function to run in the child just before exec()
230 * @user_data: user data for @child_setup
231 * @standard_output: return location for child output
232 * @standard_error: return location for child error messages
233 * @exit_status: child exit status, as returned by waitpid()
234 * @error: return location for error
236 * Executes a child synchronously (waits for the child to exit before returning).
237 * All output from the child is stored in @standard_output and @standard_error,
238 * if those parameters are non-NULL. If @exit_status is non-NULL, the exit status
239 * of the child is stored there as it would be by waitpid(); standard UNIX
240 * macros such as WIFEXITED() and WEXITSTATUS() must be used to evaluate the
241 * exit status. If an error occurs, no data is returned in @standard_output,
242 * @standard_error, or @exit_status.
244 * This function calls g_spawn_async_with_pipes() internally; see that function
245 * for full details on the other parameters.
247 * Return value: TRUE on success, FALSE if an error was set.
250 g_spawn_sync (const gchar
*working_directory
,
254 GSpawnChildSetupFunc child_setup
,
256 gchar
**standard_output
,
257 gchar
**standard_error
,
263 GIOChannel
*outchannel
= NULL
;
264 GIOChannel
*errchannel
= NULL
;
265 GPollFD outfd
, errfd
;
271 GString
*outstr
= NULL
;
272 GString
*errstr
= NULL
;
276 g_return_val_if_fail (argv
!= NULL
, FALSE
);
277 g_return_val_if_fail (!(flags
& G_SPAWN_DO_NOT_REAP_CHILD
), FALSE
);
278 g_return_val_if_fail (standard_output
== NULL
||
279 !(flags
& G_SPAWN_STDOUT_TO_DEV_NULL
), FALSE
);
280 g_return_val_if_fail (standard_error
== NULL
||
281 !(flags
& G_SPAWN_STDERR_TO_DEV_NULL
), FALSE
);
283 /* Just to ensure segfaults if callers try to use
284 * these when an error is reported.
287 *standard_output
= NULL
;
290 *standard_error
= NULL
;
292 if (!fork_exec_with_pipes (FALSE
,
296 !(flags
& G_SPAWN_LEAVE_DESCRIPTORS_OPEN
),
297 (flags
& G_SPAWN_SEARCH_PATH
) != 0,
298 (flags
& G_SPAWN_STDOUT_TO_DEV_NULL
) != 0,
299 (flags
& G_SPAWN_STDERR_TO_DEV_NULL
) != 0,
300 (flags
& G_SPAWN_CHILD_INHERITS_STDIN
) != 0,
304 standard_output
? &outpipe
: NULL
,
305 standard_error
? &errpipe
: NULL
,
310 /* Read data from child. */
316 outstr
= g_string_new ("");
317 outchannel
= g_io_channel_win32_new_fd (outpipe
);
318 g_io_channel_win32_make_pollfd (outchannel
,
319 G_IO_IN
| G_IO_ERR
| G_IO_HUP
,
325 errstr
= g_string_new ("");
326 errchannel
= g_io_channel_win32_new_fd (errpipe
);
327 g_io_channel_win32_make_pollfd (errchannel
,
328 G_IO_IN
| G_IO_ERR
| G_IO_HUP
,
332 /* Read data until we get EOF on both pipes. */
352 g_print ("%s:g_spawn_sync: calling g_io_channel_win32_poll, nfds=%d\n",
355 ret
= g_io_channel_win32_poll (fds
, nfds
, -1);
364 _("Unexpected error in g_io_channel_win32_poll() reading data from a child process"));
369 if (outpipe
>= 0 && (fds
[outindex
].revents
& G_IO_IN
))
371 switch (read_data (outstr
, outchannel
, error
))
375 g_print ("g_spawn_sync: outchannel: READ_FAILED\n");
380 g_print ("g_spawn_sync: outchannel: READ_EOF\n");
381 g_io_channel_unref (outchannel
);
383 close_and_invalidate (&outpipe
);
387 g_print ("g_spawn_sync: outchannel: OK\n");
395 if (errpipe
>= 0 && (fds
[errindex
].revents
& G_IO_IN
))
397 switch (read_data (errstr
, errchannel
, error
))
401 g_print ("g_spawn_sync: errchannel: READ_FAILED\n");
406 g_print ("g_spawn_sync: errchannel: READ_EOF\n");
407 g_io_channel_unref (errchannel
);
409 close_and_invalidate (&errpipe
);
413 g_print ("g_spawn_sync: errchannel: OK\n");
422 /* These should only be open still if we had an error. */
424 if (outchannel
!= NULL
)
425 g_io_channel_unref (outchannel
);
426 if (errchannel
!= NULL
)
427 g_io_channel_unref (errchannel
);
429 close_and_invalidate (&outpipe
);
431 close_and_invalidate (&errpipe
);
436 g_string_free (outstr
, TRUE
);
438 g_string_free (errstr
, TRUE
);
445 *exit_status
= status
;
448 *standard_output
= g_string_free (outstr
, FALSE
);
451 *standard_error
= g_string_free (errstr
, FALSE
);
458 * g_spawn_async_with_pipes:
459 * @working_directory: child's current working directory, or NULL to inherit parent's
460 * @argv: child's argument vector
461 * @envp: child's environment, or NULL to inherit parent's
462 * @flags: flags from #GSpawnFlags
463 * @child_setup: function to run in the child just before exec()
464 * @user_data: user data for @child_setup
465 * @child_pid: return location for child process ID, or NULL
466 * @standard_input: return location for file descriptor to write to child's stdin, or NULL
467 * @standard_output: return location for file descriptor to read child's stdout, or NULL
468 * @standard_error: return location for file descriptor to read child's stderr, or NULL
469 * @error: return location for error
471 * Executes a child program asynchronously (your program will not
472 * block waiting for the child to exit). The child program is
473 * specified by the only argument that must be provided, @argv. @argv
474 * should be a NULL-terminated array of strings, to be passed as the
475 * argument vector for the child. The first string in @argv is of
476 * course the name of the program to execute. By default, the name of
477 * the program must be a full path; the PATH shell variable will only
478 * be searched if you pass the %G_SPAWN_SEARCH_PATH flag.
480 * @envp is a NULL-terminated array of strings, where each string
481 * has the form <literal>KEY=VALUE</literal>. This will become
482 * the child's environment. If @envp is NULL, the child inherits its
483 * parent's environment.
485 * @flags should be the bitwise OR of any flags you want to affect the
486 * function's behavior. The %G_SPAWN_DO_NOT_REAP_CHILD means that the
487 * child will not be automatically reaped; you must call waitpid() or
488 * handle SIGCHLD yourself, or the child will become a zombie.
489 * %G_SPAWN_LEAVE_DESCRIPTORS_OPEN means that the parent's open file
490 * descriptors will be inherited by the child; otherwise all
491 * descriptors except stdin/stdout/stderr will be closed before
492 * calling exec() in the child. %G_SPAWN_SEARCH_PATH means that
493 * <literal>argv[0]</literal> need not be an absolute path, it
494 * will be looked for in the user's PATH. %G_SPAWN_STDOUT_TO_DEV_NULL
495 * means that the child's standad output will be discarded, instead
496 * of going to the same location as the parent's standard output.
497 * %G_SPAWN_STDERR_TO_DEV_NULL means that the child's standard error
498 * will be discarded. %G_SPAWN_CHILD_INHERITS_STDIN means that
499 * the child will inherit the parent's standard input (by default,
500 * the child's standard input is attached to /dev/null).
502 * @child_setup and @user_data are a function and user data to be
503 * called in the child after GLib has performed all the setup it plans
504 * to perform (including creating pipes, closing file descriptors,
505 * etc.) but before calling exec(). That is, @child_setup is called
506 * just before calling exec() in the child. Obviously actions taken in
507 * this function will only affect the child, not the parent.
509 * If non-NULL, @child_pid will be filled with the child's process
510 * ID. You can use the process ID to send signals to the child, or
511 * to waitpid() if you specified the %G_SPAWN_DO_NOT_REAP_CHILD flag.
513 * If non-NULL, the @standard_input, @standard_output, @standard_error
514 * locations will be filled with file descriptors for writing to the child's
515 * standard input or reading from its standard output or standard error.
516 * The caller of g_spawn_async_with_pipes() must close these file descriptors
517 * when they are no longer in use. If these parameters are NULL, the
518 * corresponding pipe won't be created.
520 * @error can be NULL to ignore errors, or non-NULL to report errors.
521 * If an error is set, the function returns FALSE. Errors
522 * are reported even if they occur in the child (for example if the
523 * executable in <literal>argv[0]</literal> is not found). Typically
524 * the <literal>message</literal> field of returned errors should be displayed
525 * to users. Possible errors are those from the #G_SPAWN_ERROR domain.
527 * If an error occurs, @child_pid, @standard_input, @standard_output,
528 * and @standard_error will not be filled with valid values.
530 * Return value: TRUE on success, FALSE if an error was set
533 g_spawn_async_with_pipes (const gchar
*working_directory
,
537 GSpawnChildSetupFunc child_setup
,
540 gint
*standard_input
,
541 gint
*standard_output
,
542 gint
*standard_error
,
545 g_return_val_if_fail (argv
!= NULL
, FALSE
);
546 g_return_val_if_fail (standard_output
== NULL
||
547 !(flags
& G_SPAWN_STDOUT_TO_DEV_NULL
), FALSE
);
548 g_return_val_if_fail (standard_error
== NULL
||
549 !(flags
& G_SPAWN_STDERR_TO_DEV_NULL
), FALSE
);
550 /* can't inherit stdin if we have an input pipe. */
551 g_return_val_if_fail (standard_input
== NULL
||
552 !(flags
& G_SPAWN_CHILD_INHERITS_STDIN
), FALSE
);
554 return fork_exec_with_pipes (!(flags
& G_SPAWN_DO_NOT_REAP_CHILD
),
558 !(flags
& G_SPAWN_LEAVE_DESCRIPTORS_OPEN
),
559 (flags
& G_SPAWN_SEARCH_PATH
) != 0,
560 (flags
& G_SPAWN_STDOUT_TO_DEV_NULL
) != 0,
561 (flags
& G_SPAWN_STDERR_TO_DEV_NULL
) != 0,
562 (flags
& G_SPAWN_CHILD_INHERITS_STDIN
) != 0,
573 * g_spawn_command_line_sync:
574 * @command_line: a command line
575 * @standard_output: return location for child output
576 * @standard_error: return location for child errors
577 * @exit_status: return location for child exit status
578 * @error: return location for errors
580 * A simple version of g_spawn_sync() with little-used parameters
581 * removed, taking a command line instead of an argument vector. See
582 * g_spawn_sync() for full details. @command_line will be parsed by
583 * g_shell_parse_argv(). Unlike g_spawn_sync(), the %G_SPAWN_SEARCH_PATH flag
584 * is enabled. Note that %G_SPAWN_SEARCH_PATH can have security
585 * implications, so consider using g_spawn_sync() directly if
586 * appropriate. Possible errors are those from g_spawn_sync() and those
587 * from g_shell_parse_argv().
589 * Return value: TRUE on success, FALSE if an error was set
592 g_spawn_command_line_sync (const gchar
*command_line
,
593 gchar
**standard_output
,
594 gchar
**standard_error
,
601 g_return_val_if_fail (command_line
!= NULL
, FALSE
);
603 if (!g_shell_parse_argv (command_line
,
608 retval
= g_spawn_sync (NULL
,
624 * g_spawn_command_line_async:
625 * @command_line: a command line
626 * @error: return location for errors
628 * A simple version of g_spawn_async() that parses a command line with
629 * g_shell_parse_argv() and passes it to g_spawn_async(). Runs a
630 * command line in the background. Unlike g_spawn_async(), the
631 * %G_SPAWN_SEARCH_PATH flag is enabled, other flags are not. Note
632 * that %G_SPAWN_SEARCH_PATH can have security implications, so
633 * consider using g_spawn_async() directly if appropriate. Possible
634 * errors are those from g_shell_parse_argv() and g_spawn_async().
636 * Return value: TRUE on success, FALSE if error is set.
639 g_spawn_command_line_async (const gchar
*command_line
,
645 g_return_val_if_fail (command_line
!= NULL
, FALSE
);
647 if (!g_shell_parse_argv (command_line
,
652 retval
= g_spawn_async (NULL
,
666 do_exec (gboolean dont_wait
,
667 gint child_err_report_fd
,
671 const gchar
*working_directory
,
674 gboolean close_descriptors
,
675 gboolean search_path
,
676 gboolean stdout_to_null
,
677 gboolean stderr_to_null
,
678 gboolean child_inherits_stdin
,
679 GSpawnChildSetupFunc child_setup
,
683 gchar args
[ARG_COUNT
][10];
692 new_argv
= g_new (gchar
*, argc
+ 1 + ARG_COUNT
);
694 new_argv
[0] = "gspawn-win32-helper";
695 sprintf (args
[ARG_CHILD_ERR_REPORT
], "%d", child_err_report_fd
);
696 new_argv
[ARG_CHILD_ERR_REPORT
] = args
[ARG_CHILD_ERR_REPORT
];
700 sprintf (args
[ARG_STDIN
], "%d", stdin_fd
);
701 new_argv
[ARG_STDIN
] = args
[ARG_STDIN
];
703 else if (child_inherits_stdin
)
705 /* Let stdin be alone */
706 new_argv
[ARG_STDIN
] = "-";
710 /* Keep process from blocking on a read of stdin */
711 new_argv
[ARG_STDIN
] = "z";
716 sprintf (args
[ARG_STDOUT
], "%d", stdout_fd
);
717 new_argv
[ARG_STDOUT
] = args
[ARG_STDOUT
];
719 else if (stdout_to_null
)
721 new_argv
[ARG_STDOUT
] = "z";
725 new_argv
[ARG_STDOUT
] = "-";
730 sprintf (args
[ARG_STDERR
], "%d", stderr_fd
);
731 new_argv
[ARG_STDERR
] = args
[ARG_STDERR
];
733 else if (stderr_to_null
)
735 new_argv
[ARG_STDERR
] = "z";
739 new_argv
[ARG_STDERR
] = "-";
742 if (working_directory
&& *working_directory
)
743 new_argv
[ARG_WORKING_DIRECTORY
] = working_directory
;
745 new_argv
[ARG_WORKING_DIRECTORY
] = "-";
747 if (close_descriptors
)
748 new_argv
[ARG_CLOSE_DESCRIPTORS
] = "y";
750 new_argv
[ARG_CLOSE_DESCRIPTORS
] = "-";
753 new_argv
[ARG_USE_PATH
] = "y";
755 new_argv
[ARG_USE_PATH
] = "-";
758 new_argv
[ARG_WAIT
] = "-";
760 new_argv
[ARG_WAIT
] = "w";
762 for (i
= 0; i
<= argc
; i
++)
763 new_argv
[ARG_PROGRAM
+ i
] = argv
[i
];
765 /* Call user function just before we execute the helper program,
766 * which executes the program. Dunno what's the usefulness of this.
767 * A child setup function used on Unix probably isn't of much use
768 * as such on Win32, anyhow.
772 (* child_setup
) (user_data
);
777 g_print ("calling gspawn-win32-helper with argv:\n");
778 for (i
= 0; i
< argc
+ 1 + ARG_COUNT
; i
++)
779 g_print ("argv[%d]: %s\n", i
, (new_argv
[i
] ? new_argv
[i
] : "NULL"));
783 /* Let's hope envp hasn't mucked with PATH so that
784 * gspawn-win32-helper.exe isn't found.
786 spawnvpe (P_NOWAIT
, "gspawn-win32-helper", new_argv
, envp
);
788 spawnvp (P_NOWAIT
, "gspawn-win32-helper", new_argv
);
790 /* FIXME: What if gspawn-win32-helper.exe isn't found? */
792 /* Close the child_err_report_fd and the other process's ends of the
793 * pipes in this process, otherwise the reader will never get
796 close (child_err_report_fd
);
818 while (bytes
< sizeof(gint
)*n_ints_in_buf
)
823 g_print ("%s:read_ints: trying to read %d bytes from pipe...\n",
825 sizeof(gint
)*n_ints_in_buf
- bytes
);
827 chunk
= read (fd
, ((gchar
*)buf
) + bytes
,
828 sizeof(gint
)*n_ints_in_buf
- bytes
);
831 g_print ("... got %d bytes\n", chunk
);
835 /* Some weird shit happened, bail out */
839 G_SPAWN_ERROR_FAILED
,
840 _("Failed to read from child pipe (%s)"),
851 *n_ints_read
= bytes
/sizeof(gint
);
857 fork_exec_with_pipes (gboolean dont_wait
,
858 const gchar
*working_directory
,
861 gboolean close_descriptors
,
862 gboolean search_path
,
863 gboolean stdout_to_null
,
864 gboolean stderr_to_null
,
865 gboolean child_inherits_stdin
,
866 GSpawnChildSetupFunc child_setup
,
868 gint
*standard_input
,
869 gint
*standard_output
,
870 gint
*standard_error
,
874 gint stdin_pipe
[2] = { -1, -1 };
875 gint stdout_pipe
[2] = { -1, -1 };
876 gint stderr_pipe
[2] = { -1, -1 };
877 gint child_err_report_pipe
[2] = { -1, -1 };
883 if (!make_pipe (child_err_report_pipe
, error
))
886 if (standard_input
&& !make_pipe (stdin_pipe
, error
))
887 goto cleanup_and_fail
;
889 if (standard_output
&& !make_pipe (stdout_pipe
, error
))
890 goto cleanup_and_fail
;
892 if (standard_error
&& !make_pipe (stderr_pipe
, error
))
893 goto cleanup_and_fail
;
895 status
= do_exec (dont_wait
,
896 child_err_report_pipe
[1],
907 child_inherits_stdin
,
911 if (!read_ints (child_err_report_pipe
[0],
914 goto cleanup_and_fail
;
918 /* Error from the child. */
925 case CHILD_CHDIR_FAILED
:
929 _("Failed to change to directory '%s' (%s)"),
931 g_strerror (buf
[1]));
932 goto cleanup_and_fail
;
934 case CHILD_SPAWN_FAILED
:
937 G_SPAWN_ERROR_FAILED
,
938 _("Failed to execute child process (%s)"),
939 g_strerror (buf
[1]));
940 goto cleanup_and_fail
;
944 /* Success against all odds! return the information */
947 *standard_input
= stdin_pipe
[1];
949 *standard_output
= stdout_pipe
[0];
951 *standard_error
= stderr_pipe
[0];
953 *exit_status
= status
;
958 close_and_invalidate (&child_err_report_pipe
[0]);
959 close_and_invalidate (&child_err_report_pipe
[1]);
960 close_and_invalidate (&stdin_pipe
[0]);
961 close_and_invalidate (&stdin_pipe
[1]);
962 close_and_invalidate (&stdout_pipe
[0]);
963 close_and_invalidate (&stdout_pipe
[1]);
964 close_and_invalidate (&stderr_pipe
[0]);
965 close_and_invalidate (&stderr_pipe
[1]);
971 make_pipe (gint p
[2],
978 G_SPAWN_ERROR_FAILED
,
979 _("Failed to create pipe for communicating with child process (%s)"),
987 #endif /* !GSPAWN_HELPER */