/* GIO - GLib Input, Output and Streaming Library * * Copyright © 2012 Red Hat, Inc. * Copyright © 2012-2013 Canonical Limited * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published * by the Free Software Foundation; either version 2 of the licence or (at * your option) any later version. * * See the included COPYING file for more information. * * Authors: Colin Walters * Ryan Lortie */ /** * SECTION:gsubprocess * @title: GSubprocess * @short_description: Child processes * @see_also: #GSubprocessLauncher * * #GSubprocess allows the creation of and interaction with child * processes. * * Processes can be communicated with using standard GIO-style APIs (ie: * #GInputStream, #GOutputStream). There are GIO-style APIs to wait for * process termination (ie: cancellable and with an asynchronous * variant). * * There is an API to force a process to terminate, as well as a * race-free API for sending UNIX signals to a subprocess. * * One major advantage that GIO brings over the core GLib library is * comprehensive API for asynchronous I/O, such * g_output_stream_splice_async(). This makes GSubprocess * significantly more powerful and flexible than equivalent APIs in * some other languages such as the subprocess.py * included with Python. For example, using #GSubprocess one could * create two child processes, reading standard output from the first, * processing it, and writing to the input stream of the second, all * without blocking the main loop. * * A powerful g_subprocess_communicate() API is provided similar to the * communicate() method of * subprocess.py. This enables very easy interaction * with a subprocess that has been opened with pipes. * * #GSubprocess defaults to tight control over the file descriptors open * in the child process, avoiding dangling-fd issues that are caused by * a simple fork()/exec(). The only open file descriptors in the * spawned process are ones that were explicitly specified by the * #GSubprocess API (unless %G_SUBPROCESS_FLAGS_INHERIT_FDS was * specified). * * #GSubprocess will quickly reap all child processes as they exit, * avoiding "zombie processes" remaining around for long periods of * time. g_subprocess_wait() can be used to wait for this to happen, * but it will happen even without the call being explicitly made. * * As a matter of principle, #GSubprocess has no API that accepts * shell-style space-separated strings. It will, however, match the * typical shell behaviour of searching the PATH for executables that do * not contain a directory separator in their name. * * #GSubprocess attempts to have a very simple API for most uses (ie: * spawning a subprocess with arguments and support for most typical * kinds of input and output redirection). See g_subprocess_new(). The * #GSubprocessLauncher API is provided for more complicated cases * (advanced types of redirection, environment variable manipulation, * change of working directory, child setup functions, etc). * * A typical use of #GSubprocess will involve calling * g_subprocess_new(), followed by g_subprocess_wait() or * g_subprocess_wait_sync(). After the process exits, the status can be * checked using functions such as g_subprocess_get_if_exited() (which * are similar to the familiar WIFEXITED-style POSIX macros). * * Since: 2.36 **/ #include "config.h" #include "gsubprocess.h" #include "gsubprocesslauncher-private.h" #include "gasyncresult.h" #include "giostream.h" #include "gmemoryinputstream.h" #include "glibintl.h" #include "glib-private.h" #include #ifdef G_OS_UNIX #include #include #include #include #include #include #endif #ifdef G_OS_WIN32 #define _WIN32_WINNT 0x0500 #include #include "giowin32-priv.h" #endif #ifndef O_BINARY #define O_BINARY 0 #endif #define COMMUNICATE_READ_SIZE 4096 /* A GSubprocess can have two possible states: running and not. * * These two states are reflected by the value of 'pid'. If it is * non-zero then the process is running, with that pid. * * When a GSubprocess is first created with g_object_new() it is not * running. When it is finalized, it is also not running. * * During initable_init(), if the g_spawn() is successful then we * immediately register a child watch and take an extra ref on the * subprocess. That reference doesn't drop until the child has quit, * which is why finalize can only happen in the non-running state. In * the event that the g_spawn() failed we will still be finalizing a * non-running GSubprocess (before returning from g_subprocess_new()) * with NULL. * * We make extensive use of the glib worker thread to guarantee * race-free operation. As with all child watches, glib calls waitpid() * in the worker thread. It reports the child exiting to us via the * worker thread (which means that we can do synchronous waits without * running a separate loop). We also send signals to the child process * via the worker thread so that we don't race with waitpid() and * accidentally send a signal to an already-reaped child. */ static void initable_iface_init (GInitableIface *initable_iface); typedef GObjectClass GSubprocessClass; struct _GSubprocess { GObject parent; /* only used during construction */ GSubprocessLauncher *launcher; GSubprocessFlags flags; gchar **argv; /* state tracking variables */ gchar identifier[24]; int status; GPid pid; /* list of GTask */ GMutex pending_waits_lock; GSList *pending_waits; /* These are the streams created if a pipe is requested via flags. */ GOutputStream *stdin_pipe; GInputStream *stdout_pipe; GInputStream *stderr_pipe; }; G_DEFINE_TYPE_WITH_CODE (GSubprocess, g_subprocess, G_TYPE_OBJECT, G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE, initable_iface_init)); enum { PROP_0, PROP_FLAGS, PROP_ARGV, N_PROPS }; typedef struct { gint fds[3]; GSpawnChildSetupFunc child_setup_func; gpointer child_setup_data; GArray *basic_fd_assignments; GArray *needdup_fd_assignments; } ChildData; static void unset_cloexec (int fd) { int flags; int result; flags = fcntl (fd, F_GETFD, 0); if (flags != -1) { flags &= (~FD_CLOEXEC); do result = fcntl (fd, F_SETFD, flags); while (result == -1 && errno == EINTR); } } /** * Based on code derived from * gnome-terminal:src/terminal-screen.c:terminal_screen_child_setup(), * used under the LGPLv2+ with permission from author. */ static void child_setup (gpointer user_data) { ChildData *child_data = user_data; gint i; gint result; /* We're on the child side now. "Rename" the file descriptors in * child_data.fds[] to stdin/stdout/stderr. * * We don't close the originals. It's possible that the originals * should not be closed and if they should be closed then they should * have been created O_CLOEXEC. */ for (i = 0; i < 3; i++) if (child_data->fds[i] != -1 && child_data->fds[i] != i) { do result = dup2 (child_data->fds[i], i); while (result == -1 && errno == EINTR); } /* Basic fd assignments we can just unset FD_CLOEXEC */ if (child_data->basic_fd_assignments) { for (i = 0; i < child_data->basic_fd_assignments->len; i++) { gint fd = g_array_index (child_data->basic_fd_assignments, int, i); unset_cloexec (fd); } } /* If we're doing remapping fd assignments, we need to handle * the case where the user has specified e.g.: * 5 -> 4, 4 -> 6 * * We do this by duping the source fds temporarily. */ if (child_data->needdup_fd_assignments) { for (i = 0; i < child_data->needdup_fd_assignments->len; i += 2) { gint parent_fd = g_array_index (child_data->needdup_fd_assignments, int, i); gint new_parent_fd; do new_parent_fd = fcntl (parent_fd, F_DUPFD_CLOEXEC, 3); while (parent_fd == -1 && errno == EINTR); g_array_index (child_data->needdup_fd_assignments, int, i) = new_parent_fd; } for (i = 0; i < child_data->needdup_fd_assignments->len; i += 2) { gint parent_fd = g_array_index (child_data->needdup_fd_assignments, int, i); gint child_fd = g_array_index (child_data->needdup_fd_assignments, int, i+1); if (parent_fd == child_fd) { unset_cloexec (parent_fd); } else { do result = dup2 (parent_fd, child_fd); while (result == -1 && errno == EINTR); (void) close (parent_fd); } } } if (child_data->child_setup_func) child_data->child_setup_func (child_data->child_setup_data); } static GInputStream * platform_input_stream_from_spawn_fd (gint fd) { if (fd < 0) return NULL; #ifdef G_OS_UNIX return g_unix_input_stream_new (fd, TRUE); #else return g_win32_input_stream_new_from_fd (fd, TRUE); #endif } static GOutputStream * platform_output_stream_from_spawn_fd (gint fd) { if (fd < 0) return NULL; #ifdef G_OS_UNIX return g_unix_output_stream_new (fd, TRUE); #else return g_win32_output_stream_new_from_fd (fd, TRUE); #endif } #ifdef G_OS_UNIX static gint unix_open_file (const char *filename, gint mode, GError **error) { gint my_fd; my_fd = g_open (filename, mode | O_BINARY | O_CLOEXEC, 0666); /* If we return -1 we should also set the error */ if (my_fd < 0) { gint saved_errno = errno; char *display_name; display_name = g_filename_display_name (filename); g_set_error (error, G_IO_ERROR, g_io_error_from_errno (saved_errno), _("Error opening file '%s': %s"), display_name, g_strerror (saved_errno)); g_free (display_name); /* fall through... */ } return my_fd; } #endif static void g_subprocess_set_property (GObject *object, guint prop_id, const GValue *value, GParamSpec *pspec) { GSubprocess *self = G_SUBPROCESS (object); switch (prop_id) { case PROP_FLAGS: self->flags = g_value_get_flags (value); break; case PROP_ARGV: self->argv = g_value_dup_boxed (value); break; default: g_assert_not_reached (); } } static gboolean g_subprocess_exited (GPid pid, gint status, gpointer user_data) { GSubprocess *self = user_data; GSList *tasks; g_assert (self->pid == pid); g_mutex_lock (&self->pending_waits_lock); self->status = status; tasks = self->pending_waits; self->pending_waits = NULL; self->pid = 0; g_mutex_unlock (&self->pending_waits_lock); /* Signal anyone in g_subprocess_wait_async() to wake up now */ while (tasks) { g_task_return_boolean (tasks->data, TRUE); tasks = g_slist_delete_link (tasks, tasks); } g_spawn_close_pid (pid); return FALSE; } static gboolean initable_init (GInitable *initable, GCancellable *cancellable, GError **error) { GSubprocess *self = G_SUBPROCESS (initable); ChildData child_data = { { -1, -1, -1 }, 0 }; gint *pipe_ptrs[3] = { NULL, NULL, NULL }; gint pipe_fds[3] = { -1, -1, -1 }; gint close_fds[3] = { -1, -1, -1 }; GSpawnFlags spawn_flags = 0; gboolean success = FALSE; gint i; /* this is a programmer error */ if (!self->argv || !self->argv[0] || !self->argv[0][0]) return FALSE; if (g_cancellable_set_error_if_cancelled (cancellable, error)) return FALSE; /* We must setup the three fds that will end up in the child as stdin, * stdout and stderr. * * First, stdin. */ if (self->flags & G_SUBPROCESS_FLAGS_STDIN_INHERIT) spawn_flags |= G_SPAWN_CHILD_INHERITS_STDIN; else if (self->flags & G_SUBPROCESS_FLAGS_STDIN_PIPE) pipe_ptrs[0] = &pipe_fds[0]; #ifdef G_OS_UNIX else if (self->launcher) { if (self->launcher->stdin_fd != -1) child_data.fds[0] = self->launcher->stdin_fd; else if (self->launcher->stdin_path != NULL) { child_data.fds[0] = close_fds[0] = unix_open_file (self->launcher->stdin_path, O_RDONLY, error); if (child_data.fds[0] == -1) goto out; } } #endif /* Next, stdout. */ if (self->flags & G_SUBPROCESS_FLAGS_STDOUT_SILENCE) spawn_flags |= G_SPAWN_STDOUT_TO_DEV_NULL; else if (self->flags & G_SUBPROCESS_FLAGS_STDOUT_PIPE) pipe_ptrs[1] = &pipe_fds[1]; #ifdef G_OS_UNIX else if (self->launcher) { if (self->launcher->stdout_fd != -1) child_data.fds[1] = self->launcher->stdout_fd; else if (self->launcher->stdout_path != NULL) { child_data.fds[1] = close_fds[1] = unix_open_file (self->launcher->stdout_path, O_CREAT | O_WRONLY, error); if (child_data.fds[1] == -1) goto out; } } #endif /* Finally, stderr. */ if (self->flags & G_SUBPROCESS_FLAGS_STDERR_SILENCE) spawn_flags |= G_SPAWN_STDERR_TO_DEV_NULL; else if (self->flags & G_SUBPROCESS_FLAGS_STDERR_PIPE) pipe_ptrs[2] = &pipe_fds[2]; else if (self->flags & G_SUBPROCESS_FLAGS_STDERR_MERGE) /* This will work because stderr gets setup after stdout. */ child_data.fds[2] = 1; #ifdef G_OS_UNIX else if (self->launcher) { if (self->launcher->stderr_fd != -1) child_data.fds[2] = self->launcher->stderr_fd; else if (self->launcher->stderr_path != NULL) { child_data.fds[2] = close_fds[2] = unix_open_file (self->launcher->stderr_path, O_CREAT | O_WRONLY, error); if (child_data.fds[2] == -1) goto out; } } #endif #ifdef G_OS_UNIX if (self->launcher) { child_data.basic_fd_assignments = self->launcher->basic_fd_assignments; child_data.needdup_fd_assignments = self->launcher->needdup_fd_assignments; } #endif /* argv0 has no '/' in it? We better do a PATH lookup. */ if (strchr (self->argv[0], G_DIR_SEPARATOR) == NULL) { if (self->launcher && self->launcher->path_from_envp) spawn_flags |= G_SPAWN_SEARCH_PATH_FROM_ENVP; else spawn_flags |= G_SPAWN_SEARCH_PATH; } if (self->flags & G_SUBPROCESS_FLAGS_INHERIT_FDS) spawn_flags |= G_SPAWN_LEAVE_DESCRIPTORS_OPEN; spawn_flags |= G_SPAWN_DO_NOT_REAP_CHILD; spawn_flags |= G_SPAWN_CLOEXEC_PIPES; child_data.child_setup_func = self->launcher ? self->launcher->child_setup_func : NULL; child_data.child_setup_data = self->launcher ? self->launcher->child_setup_user_data : NULL; success = g_spawn_async_with_pipes (self->launcher ? self->launcher->cwd : NULL, self->argv, self->launcher ? self->launcher->envp : NULL, spawn_flags, child_setup, &child_data, &self->pid, pipe_ptrs[0], pipe_ptrs[1], pipe_ptrs[2], error); g_assert (success == (self->pid != 0)); { guint64 identifier; gint s; #ifdef G_OS_WIN32 identifier = (guint64) GetProcessId (self->pid); #else identifier = (guint64) self->pid; #endif s = snprintf (self->identifier, sizeof self->identifier, "%"G_GUINT64_FORMAT, identifier); g_assert (0 < s && s < sizeof self->identifier); } /* Start attempting to reap the child immediately */ if (success) { GMainContext *worker_context; GSource *source; worker_context = GLIB_PRIVATE_CALL (g_get_worker_context) (); source = g_child_watch_source_new (self->pid); g_source_set_callback (source, (GSourceFunc) g_subprocess_exited, g_object_ref (self), g_object_unref); g_source_attach (source, worker_context); g_source_unref (source); } out: /* we don't need this past init... */ self->launcher = NULL; for (i = 0; i < 3; i++) if (close_fds[i] != -1) close (close_fds[i]); self->stdin_pipe = platform_output_stream_from_spawn_fd (pipe_fds[0]); self->stdout_pipe = platform_input_stream_from_spawn_fd (pipe_fds[1]); self->stderr_pipe = platform_input_stream_from_spawn_fd (pipe_fds[2]); return success; } static void g_subprocess_finalize (GObject *object) { GSubprocess *self = G_SUBPROCESS (object); g_assert (self->pending_waits == NULL); g_assert (self->pid == 0); g_clear_object (&self->stdin_pipe); g_clear_object (&self->stdout_pipe); g_clear_object (&self->stderr_pipe); g_free (self->argv); G_OBJECT_CLASS (g_subprocess_parent_class)->finalize (object); } static void g_subprocess_init (GSubprocess *self) { } static void initable_iface_init (GInitableIface *initable_iface) { initable_iface->init = initable_init; } static void g_subprocess_class_init (GSubprocessClass *class) { GObjectClass *gobject_class = G_OBJECT_CLASS (class); gobject_class->finalize = g_subprocess_finalize; gobject_class->set_property = g_subprocess_set_property; g_object_class_install_property (gobject_class, PROP_FLAGS, g_param_spec_flags ("flags", P_("Flags"), P_("Subprocess flags"), G_TYPE_SUBPROCESS_FLAGS, 0, G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_ARGV, g_param_spec_boxed ("argv", P_("Arguments"), P_("Argument vector"), G_TYPE_STRV, G_PARAM_WRITABLE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS)); } /** * g_subprocess_new: (skip) * * Create a new process with the given flags and varargs argument list. * * The argument list must be terminated with %NULL. * * Returns: A newly created #GSubprocess, or %NULL on error (and @error * will be set) * * Since: 2.36 */ GSubprocess * g_subprocess_new (GSubprocessFlags flags, GError **error, const gchar *argv0, ...) { GSubprocess *result; GPtrArray *args; const gchar *arg; va_list ap; g_return_val_if_fail (argv0 != NULL && argv0[0] != '\0', NULL); g_return_val_if_fail (error == NULL || *error == NULL, NULL); args = g_ptr_array_new (); va_start (ap, argv0); g_ptr_array_add (args, (gchar *) argv0); while ((arg = va_arg (ap, const gchar *))) g_ptr_array_add (args, (gchar *) arg); g_ptr_array_add (args, NULL); result = g_subprocess_newv ((const gchar * const *) args->pdata, flags, error); g_ptr_array_free (args, TRUE); return result; } /** * g_subprocess_newv: * * Create a new process with the given flags and argument list. * * The argument list is expected to be %NULL-terminated. * * Returns: A newly created #GSubprocess, or %NULL on error (and @error * will be set) * * Since: 2.36 * Rename to: g_subprocess_new */ GSubprocess * g_subprocess_newv (const gchar * const *argv, GSubprocessFlags flags, GError **error) { g_return_val_if_fail (argv != NULL && argv[0] != NULL && argv[0][0] != '\0', NULL); return g_initable_new (G_TYPE_SUBPROCESS, NULL, error, "argv", argv, "flags", flags, NULL); } const gchar * g_subprocess_get_identifier (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), NULL); if (self->pid) return self->identifier; else return NULL; } GOutputStream * g_subprocess_get_stdin_pipe (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), NULL); g_return_val_if_fail (self->stdin_pipe, NULL); return self->stdin_pipe; } GInputStream * g_subprocess_get_stdout_pipe (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), NULL); g_return_val_if_fail (self->stdout_pipe, NULL); return self->stdout_pipe; } GInputStream * g_subprocess_get_stderr_pipe (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), NULL); g_return_val_if_fail (self->stderr_pipe, NULL); return self->stderr_pipe; } static void g_subprocess_wait_cancelled (GCancellable *cancellable, gpointer user_data) { GTask *task = user_data; GSubprocess *self; self = g_task_get_source_object (task); g_mutex_lock (&self->pending_waits_lock); self->pending_waits = g_slist_remove (self->pending_waits, task); g_mutex_unlock (&self->pending_waits_lock); g_task_return_boolean (task, FALSE); g_object_unref (task); } void g_subprocess_wait_async (GSubprocess *self, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { GTask *task; task = g_task_new (self, cancellable, callback, user_data); g_mutex_lock (&self->pending_waits_lock); if (self->pid) { /* Only bother with cancellable if we're putting it in the list. * If not, it's going to dispatch immediately anyway and we will * see the cancellation in the _finish(). */ if (cancellable) g_signal_connect_object (cancellable, "cancelled", G_CALLBACK (g_subprocess_wait_cancelled), task, 0); self->pending_waits = g_slist_prepend (self->pending_waits, task); task = NULL; } g_mutex_unlock (&self->pending_waits_lock); /* If we still have task then it's because did_exit is already TRUE */ if (task != NULL) { g_task_return_boolean (task, TRUE); g_object_unref (task); } } gboolean g_subprocess_wait_finish (GSubprocess *self, GAsyncResult *result, GError **error) { return g_task_propagate_boolean (G_TASK (result), error); } /* Some generic helpers for emulating synchronous operations using async * operations. */ static void g_subprocess_sync_setup (void) { g_main_context_push_thread_default (g_main_context_new ()); } static void g_subprocess_sync_done (GObject *source_object, GAsyncResult *result, gpointer user_data) { GAsyncResult **result_ptr = user_data; *result_ptr = g_object_ref (result); } static void g_subprocess_sync_complete (GAsyncResult **result) { GMainContext *context = g_main_context_get_thread_default (); while (!*result) g_main_context_iteration (context, TRUE); g_main_context_pop_thread_default (context); g_main_context_unref (context); } /** * g_subprocess_wait: * @self: a #GSubprocess * @cancellable: a #GCancellable * @error: a #GError * * Synchronously wait for the subprocess to terminate, returning the * status code in @out_exit_status. See the documentation of * g_spawn_check_exit_status() for how to interpret it. Note that if * @error is set, then @out_exit_status will be left uninitialized. * * Returns: %TRUE on success, %FALSE if @cancellable was cancelled * * Since: 2.36 */ gboolean g_subprocess_wait (GSubprocess *self, GCancellable *cancellable, GError **error) { GAsyncResult *result = NULL; gboolean success; g_return_val_if_fail (G_IS_SUBPROCESS (self), FALSE); /* Synchronous waits are actually the 'more difficult' case because we * need to deal with the possibility of cancellation. That more or * less implies that we need a main context (to dispatch either of the * possible reasons for the operation ending). * * So we make one and then do this async... */ if (g_cancellable_set_error_if_cancelled (cancellable, error)) return FALSE; /* We can shortcut in the case that the process already quit (but only * after we checked the cancellable). */ if (self->pid == 0) return TRUE; /* Otherwise, we need to do this the long way... */ g_subprocess_sync_setup (); g_subprocess_wait_async (self, cancellable, g_subprocess_sync_done, &result); g_subprocess_sync_complete (&result); success = g_subprocess_wait_finish (self, result, error); g_object_unref (result); return success; } /** * g_subprocess_wait_sync_check: * @self: a #GSubprocess * @cancellable: a #GCancellable * @error: a #GError * * Combines g_subprocess_wait_sync() with g_spawn_check_exit_status(). * * Returns: %TRUE on success, %FALSE if process exited abnormally, or @cancellable was cancelled * * Since: 2.36 */ gboolean g_subprocess_wait_check (GSubprocess *self, GCancellable *cancellable, GError **error) { return g_subprocess_wait (self, cancellable, error) && g_spawn_check_exit_status (self->status, error); } void g_subprocess_wait_check_async (GSubprocess *self, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { g_subprocess_wait_async (self, cancellable, callback, user_data); } gboolean g_subprocess_wait_check_finish (GSubprocess *self, GAsyncResult *result, GError **error) { return g_subprocess_wait_finish (self, result, error) && g_spawn_check_exit_status (self->status, error); } #ifdef G_OS_UNIX typedef struct { GSubprocess *subprocess; gint signalnum; } SignalRecord; static gboolean g_subprocess_actually_send_signal (gpointer user_data) { SignalRecord *signal_record = user_data; /* The pid is set to zero from the worker thread as well, so we don't * need to take a lock in order to prevent it from changing under us. */ if (signal_record->subprocess->pid) kill (signal_record->subprocess->pid, signal_record->signalnum); g_object_unref (signal_record->subprocess); g_slice_free (SignalRecord, signal_record); return FALSE; } static void g_subprocess_dispatch_signal (GSubprocess *self, gint signalnum) { SignalRecord signal_record = { g_object_ref (self), signalnum }; g_return_if_fail (G_IS_SUBPROCESS (self)); /* This MUST be a lower priority than the priority that the child * watch source uses in initable_init(). * * Reaping processes, reporting the results back to GSubprocess and * sending signals is all done in the glib worker thread. We cannot * have a kill() done after the reap and before the report without * risking killing a process that's no longer there so the kill() * needs to have the lower priority. * * G_PRIORITY_HIGH_IDLE is lower priority than G_PRIORITY_DEFAULT. */ g_main_context_invoke_full (GLIB_PRIVATE_CALL (g_get_worker_context) (), G_PRIORITY_HIGH_IDLE, g_subprocess_actually_send_signal, g_slice_dup (SignalRecord, &signal_record), NULL); } /** * g_subprocess_send_signal: * @self: a #GSubprocess * @signal_num: the signal number to send * * Sends the UNIX signal @signal_num to the subprocess, if it is still * running. * * This API is race-free. If the subprocess has terminated, it will not * be signalled. * * This API is not available on Windows. * * Since: 2.36 **/ void g_subprocess_send_signal (GSubprocess *self, gint signal_num) { g_return_if_fail (G_IS_SUBPROCESS (self)); g_subprocess_dispatch_signal (self, signal_num); } #endif /** * g_subprocess_force_exit: * @self: a #GSubprocess * * Use an operating-system specific method to attempt an immediate, * forceful termination of the process. There is no mechanism to * determine whether or not the request itself was successful; * however, you can use g_subprocess_wait() to monitor the status of * the process after calling this function. * * On Unix, this function sends %SIGKILL. * * Since: 2.36 **/ void g_subprocess_force_exit (GSubprocess *self) { g_return_if_fail (G_IS_SUBPROCESS (self)); #ifdef G_OS_UNIX g_subprocess_dispatch_signal (self, SIGKILL); #else TerminateProcess (self->pid, 1); #endif } /** * g_subprocess_get_status: * @self: a #GSubprocess * * Gets the raw status code of the process, as from waitpid(). * * This value has no particular meaning, but it can be used with the * macros defined by the system headers such as WIFEXITED. It can also * be used with g_spawn_check_exit_status(). * * It is more likely that you want to use g_subprocess_get_if_exited() * followed by g_subprocess_get_exit_status(). * * It is an error to call this function before g_subprocess_wait() has * returned. * * Returns: the (meaningless) waitpid() exit status from the kernel * * Since: 2.36 **/ gint g_subprocess_get_status (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), FALSE); g_return_val_if_fail (self->pid == 0, FALSE); return self->status; } /** * g_subprocess_get_successful: * @self: a #GSubprocess * * Checks if the process was "successful". A process is considered * successful if it exited cleanly with an exit status of 0, either by * way of the exit() system call or return from main(). * * It is an error to call this function before g_subprocess_wait() has * returned. * * Returns: %TRUE if the process exited cleanly with a exit status of 0 * * Since: 2.36 **/ gboolean g_subprocess_get_successful (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), FALSE); g_return_val_if_fail (self->pid == 0, FALSE); return WIFEXITED (self->status) && WEXITSTATUS (self->status) == 0; } /** * g_subprocess_get_if_exited: * @self: a #GSubprocess * * Check if the given subprocess exited normally (ie: by way of exit() * or return from main()). * * This is equivalent to the system WIFEXITED macro. * * It is an error to call this function before g_subprocess_wait() has * returned. * * Returns: %TRUE if the case of a normal exit * * Since: 2.36 **/ gboolean g_subprocess_get_if_exited (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), FALSE); g_return_val_if_fail (self->pid == 0, FALSE); return WIFEXITED (self->status); } /** * g_subprocess_get_exit_status: * @self: a #GSubprocess * * Check the exit status of the subprocess, given that it exited * normally. This is the value passed to the exit() system call or the * return value from main. * * This is equivalent to the system WEXITSTATUS macro. * * It is an error to call this function before g_subprocess_wait() and * unless g_subprocess_get_if_exited() returned %TRUE. * * Returns: the exit status * * Since: 2.36 **/ gint g_subprocess_get_exit_status (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), 1); g_return_val_if_fail (self->pid == 0, 1); g_return_val_if_fail (WIFEXITED (self->status), 1); return WEXITSTATUS (self->status); } /** * g_subprocess_get_if_signaled: * @self: a #GSubprocess * * Check if the given subprocess terminated in response to a signal. * * This is equivalent to the system WIFSIGNALED macro. * * It is an error to call this function before g_subprocess_wait() has * returned. * * Returns: %TRUE if the case of termination due to a signal * * Since: 2.36 **/ gboolean g_subprocess_get_if_signaled (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), FALSE); g_return_val_if_fail (self->pid == 0, FALSE); return WIFSIGNALED (self->status); } /** * g_subprocess_get_term_sig: * @self: a #GSubprocess * * Get the signal number that caused the subprocess to terminate, given * that it terminated due to a signal. * * This is equivalent to the system WTERMSIG macro. * * It is an error to call this function before g_subprocess_wait() and * unless g_subprocess_get_if_signaled() returned %TRUE. * * Returns: the signal causing termination * * Since: 2.36 **/ gint g_subprocess_get_term_sig (GSubprocess *self) { g_return_val_if_fail (G_IS_SUBPROCESS (self), 0); g_return_val_if_fail (self->pid == 0, 0); g_return_val_if_fail (WIFSIGNALED (self->status), 0); return WTERMSIG (self->status); } /*< private >*/ void g_subprocess_set_launcher (GSubprocess *subprocess, GSubprocessLauncher *launcher) { subprocess->launcher = launcher; } /* g_subprocess_communicate implementation below: * * This is a tough problem. We have to watch 5 things at the same time: * * - writing to stdin made progress * - reading from stdout made progress * - reading from stderr made progress * - process terminated * - cancellable being cancelled by caller * * We use a GMainContext for all of these (either as async function * calls or as a GSource (in the case of the cancellable). That way at * least we don't have to worry about threading. * * For the sync case we use the usual trick of creating a private main * context and iterating it until completion. * * It's very possible that the process will dump a lot of data to stdout * just before it quits, so we can easily have data to read from stdout * and see the process has terminated at the same time. We want to make * sure that we read all of the data from the pipes first, though, so we * do IO operations at a higher priority than the wait operation (which * is at G_IO_PRIORITY_DEFAULT). Even in the case that we have to do * multiple reads to get this data, the pipe() will always be polling * as ready and with the async result for the read at a higher priority, * the main context will not dispatch the completion for the wait(). * * We keep our own private GCancellable. In the event that any of the * above suffers from an error condition (including the user cancelling * their cancellable) we immediately dispatch the GTask with the error * result and fire our cancellable to cleanup any pending operations. * In the case that the error is that the user's cancellable was fired, * it's vaguely wasteful to report an error because GTask will handle * this automatically, so we just return FALSE. * * We let each pending sub-operation take a ref on the GTask of the * communicate operation. We have to be careful that we don't report * the task completion more than once, though, so we keep a flag for * that. */ typedef struct { const gchar *stdin_data; gsize stdin_length; gsize stdin_offset; GInputStream *stdin_buf; GMemoryOutputStream *stdout_buf; GMemoryOutputStream *stderr_buf; GCancellable *cancellable; GSource *cancellable_source; guint outstanding_ops; gboolean reported_error; } CommunicateState; static void g_subprocess_communicate_made_progress (GObject *source_object, GAsyncResult *result, gpointer user_data) { CommunicateState *state; GSubprocess *subprocess; GError *error = NULL; gpointer source; GTask *task; g_assert (source_object != NULL); task = user_data; subprocess = g_task_get_source_object (task); state = g_task_get_task_data (task); source = source_object; state->outstanding_ops--; if (source == subprocess->stdin_pipe || source == state->stdout_buf || source == state->stderr_buf) { (void) g_output_stream_splice_finish ((GOutputStream*)source, result, &error); } else if (source == subprocess) { (void) g_subprocess_wait_finish (subprocess, result, &error); } else g_assert_not_reached (); if (error) { /* Only report the first error we see. * * We might be seeing an error as a result of the cancellation * done when the process quits. */ if (!state->reported_error) { state->reported_error = TRUE; g_cancellable_cancel (state->cancellable); g_task_return_error (task, error); } else g_error_free (error); } else if (state->outstanding_ops == 0) { g_task_return_boolean (task, TRUE); } /* And drop the original ref */ g_object_unref (task); } static gboolean g_subprocess_communicate_cancelled (gpointer user_data) { CommunicateState *state = user_data; g_cancellable_cancel (state->cancellable); return FALSE; } static void g_subprocess_communicate_state_free (gpointer data) { CommunicateState *state = data; g_clear_object (&state->stdin_buf); g_clear_object (&state->stdout_buf); g_clear_object (&state->stderr_buf); if (!g_source_is_destroyed (state->cancellable_source)) g_source_destroy (state->cancellable_source); g_source_unref (state->cancellable_source); g_slice_free (CommunicateState, state); } static CommunicateState * g_subprocess_communicate_internal (GSubprocess *subprocess, GBytes *stdin_buf, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { CommunicateState *state; GTask *task; task = g_task_new (subprocess, cancellable, callback, user_data); state = g_slice_new0 (CommunicateState); g_task_set_task_data (task, state, g_subprocess_communicate_state_free); state->cancellable = g_cancellable_new (); if (cancellable) { state->cancellable_source = g_cancellable_source_new (cancellable); /* No ref held here, but we unref the source from state's free function */ g_source_set_callback (state->cancellable_source, g_subprocess_communicate_cancelled, state, NULL); g_source_attach (state->cancellable_source, g_main_context_get_thread_default ()); } if (subprocess->stdin_pipe) { g_assert (stdin_buf != NULL); state->stdin_buf = g_memory_input_stream_new_from_bytes (stdin_buf); g_output_stream_splice_async (subprocess->stdin_pipe, (GInputStream*)state->stdin_buf, G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET, G_PRIORITY_DEFAULT, state->cancellable, g_subprocess_communicate_made_progress, g_object_ref (task)); state->outstanding_ops++; } if (subprocess->stdout_pipe) { state->stdout_buf = (GMemoryOutputStream*)g_memory_output_stream_new_resizable (); g_output_stream_splice_async ((GOutputStream*)state->stdout_buf, subprocess->stdout_pipe, G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET, G_PRIORITY_DEFAULT, state->cancellable, g_subprocess_communicate_made_progress, g_object_ref (task)); state->outstanding_ops++; } if (subprocess->stderr_pipe) { state->stderr_buf = (GMemoryOutputStream*)g_memory_output_stream_new_resizable (); g_output_stream_splice_async ((GOutputStream*)state->stderr_buf, subprocess->stderr_pipe, G_OUTPUT_STREAM_SPLICE_CLOSE_SOURCE | G_OUTPUT_STREAM_SPLICE_CLOSE_TARGET, G_PRIORITY_DEFAULT, state->cancellable, g_subprocess_communicate_made_progress, g_object_ref (task)); state->outstanding_ops++; } g_subprocess_wait_async (subprocess, state->cancellable, g_subprocess_communicate_made_progress, g_object_ref (task)); state->outstanding_ops++; return state; } /** * g_subprocess_communicate: * @self: a #GSubprocess * @stdin_buf: data to send to the stdin of the subprocess, or %NULL * @cancellable: a #GCancellable * @stdout_buf: (out): data read from the subprocess stdout * @stderr_buf: (out): data read from the subprocess stderr * @error: a pointer to a %NULL #GError pointer, or %NULL * * Communicate with the subprocess until it terminates, and all input * and output has been completed. * * If @stdin is given, the subprocess must have been created with * %G_SUBPROCESS_FLAGS_STDIN_PIPE. The given data is fed to the * stdin of the subprocess and the pipe is closed (ie: EOF). * * At the same time (as not to cause blocking when dealing with large * amounts of data), if %G_SUBPROCESS_FLAGS_STDOUT_PIPE or * %G_SUBPROCESS_FLAGS_STDERR_PIPE were used, reads from those * streams. The data that was read is returned in @stdout and/or * the @stderr. * * If the subprocess was created with %G_SUBPROCESS_FLAGS_STDOUT_PIPE, * @stdout_buf will contain the data read from stdout. Otherwise, for * subprocesses not created with %G_SUBPROCESS_FLAGS_STDOUT_PIPE, * @stdout_buf will be set to %NULL. Similar provisions apply to * @stderr_buf and %G_SUBPROCESS_FLAGS_STDERR_PIPE. * * As usual, any output variable may be given as %NULL to ignore it. * * If you desire the stdout and stderr data to be interleaved, create * the subprocess with %G_SUBPROCESS_FLAGS_STDOUT_PIPE and * %G_SUBPROCESS_FLAGS_STDERR_MERGE. The merged result will be returned * in @stdout_buf and @stderr_buf will be set to %NULL. * * In case of any error (including cancellation), %FALSE will be * returned with @error set. Some or all of the stdin data may have * been written. Any stdout or stderr data that has been read will be * discarded. None of the out variables (aside from @error) will have * been set to anything in particular and should not be inspected. * * In the case that %TRUE is returned, the subprocess has exited and the * exit status inspection APIs (eg: g_subprocess_get_if_exited(), * g_subprocess_get_exit_status()) may be used. * * You should not attempt to use any of the subprocess pipes after * starting this function, since they may be left in strange states, * even if the operation was cancelled. You should especially not * attempt to interact with the pipes while the operation is in progress * (either from another thread or if using the asynchronous version). * * Returns: %TRUE if successful * * Since: 2.40 **/ gboolean g_subprocess_communicate (GSubprocess *subprocess, GBytes *stdin_buf, GCancellable *cancellable, GBytes **stdout_buf, GBytes **stderr_buf, GError **error) { GAsyncResult *result = NULL; gboolean success; g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE); g_return_val_if_fail (stdin_buf == NULL || (subprocess->flags & G_SUBPROCESS_FLAGS_STDIN_PIPE), FALSE); g_return_val_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable), FALSE); g_return_val_if_fail (error == NULL || *error == NULL, FALSE); g_subprocess_sync_setup (); g_subprocess_communicate_internal (subprocess, stdin_buf, cancellable, g_subprocess_sync_done, &result); g_subprocess_sync_complete (&result); success = g_subprocess_communicate_finish (subprocess, result, stdout_buf, stderr_buf, error); g_object_unref (result); return success; } /** * g_subprocess_communicate_async: * @subprocess: Self * @stdin_buf: Input data * @cancellable: Cancellable * @callback: Callback * @user_data: User data * * Asynchronous version of g_subprocess_communicate(). Complete * invocation with g_subprocess_communicate_finish(). */ void g_subprocess_communicate_async (GSubprocess *subprocess, GBytes *stdin_buf, GCancellable *cancellable, GAsyncReadyCallback callback, gpointer user_data) { g_return_if_fail (G_IS_SUBPROCESS (subprocess)); g_return_if_fail (stdin_buf == NULL || (subprocess->flags & G_SUBPROCESS_FLAGS_STDIN_PIPE)); g_return_if_fail (cancellable == NULL || G_IS_CANCELLABLE (cancellable)); g_subprocess_communicate_internal (subprocess, stdin_buf, cancellable, callback, user_data); } /** * g_subprocess_communicate_finish: * @subprocess: Self * @result: Result * @stdout_buf: (out): Return location for stdout data * @stderr_buf: (out): Return location for stderr data * @error: Error * * Complete an invocation of g_subprocess_communicate_async(). */ gboolean g_subprocess_communicate_finish (GSubprocess *subprocess, GAsyncResult *result, GBytes **stdout_buf, GBytes **stderr_buf, GError **error) { gboolean success; CommunicateState *state; g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE); g_return_val_if_fail (g_task_is_valid (result, subprocess), FALSE); g_return_val_if_fail (error == NULL || *error == NULL, FALSE); g_object_ref (result); state = g_task_get_task_data ((GTask*)result); success = g_task_propagate_boolean ((GTask*)result, error); if (success) { if (stdout_buf) *stdout_buf = g_memory_output_stream_steal_as_bytes (state->stdout_buf); if (stderr_buf) *stderr_buf = g_memory_output_stream_steal_as_bytes (state->stderr_buf); } g_object_unref (result); return success; }