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glib/gio/gsubprocess.c
Philip Withnall 4795dadde4 gsubprocess: Clear std buf outputs to NULL on failure 
Instead of sometimes returning a non-NULL buffer, always return NULL.
However, keep the documentation as explicitly returning undefined values
on failure, so that we can change the behaviour in future if needed.

The return values weren’t defined for failure before, so were
implicitly returning undefined values.

Signed-off-by: Philip Withnall <withnall@endlessm.com>
2018-10-11 11:31:27 +13:00

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright © 2012, 2013 Red Hat, Inc.
* Copyright © 2012, 2013 Canonical Limited
*
* This library 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 2.1 of the License, or (at your option) any later version.
*
* See the included COPYING file for more information.
*
* Authors: Colin Walters <walters@verbum.org>
* Ryan Lortie <desrt@desrt.ca>
*/
/**
* SECTION:gsubprocess
* @title: GSubprocess
* @short_description: Child processes
* @include: gio/gio.h
* @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_async() or
* g_subprocess_wait(). 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: 2.40
**/
#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 <string.h>
#ifdef G_OS_UNIX
#include <gio/gunixoutputstream.h>
#include <gio/gfiledescriptorbased.h>
#include <gio/gunixinputstream.h>
#include <gstdio.h>
#include <glib-unix.h>
#include <fcntl.h>
#endif
#ifdef G_OS_WIN32
#include <windows.h>
#include <io.h>
#include "giowin32-priv.h"
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC 0
#else
#define HAVE_O_CLOEXEC 1
#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
};
#ifdef G_OS_UNIX
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)
{
int errsv;
flags &= (~FD_CLOEXEC);
do
{
result = fcntl (fd, F_SETFD, flags);
errsv = errno;
}
while (result == -1 && errsv == EINTR);
}
}
static int
dupfd_cloexec (int parent_fd)
{
int fd, errsv;
#ifdef F_DUPFD_CLOEXEC
do
{
fd = fcntl (parent_fd, F_DUPFD_CLOEXEC, 3);
errsv = errno;
}
while (fd == -1 && errsv == EINTR);
#else
/* OS X Snow Lion and earlier don't have F_DUPFD_CLOEXEC:
* https://bugzilla.gnome.org/show_bug.cgi?id=710962
*/
int result, flags;
do
{
fd = fcntl (parent_fd, F_DUPFD, 3);
errsv = errno;
}
while (fd == -1 && errsv == EINTR);
flags = fcntl (fd, F_GETFD, 0);
if (flags != -1)
{
flags |= FD_CLOEXEC;
do
{
result = fcntl (fd, F_SETFD, flags);
errsv = errno;
}
while (result == -1 && errsv == EINTR);
}
#endif
return fd;
}
/*
* 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;
int errsv;
/* 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);
errsv = errno;
}
while (result == -1 && errsv == 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;
new_parent_fd = dupfd_cloexec (parent_fd);
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);
errsv = errno;
}
while (result == -1 && errsv == EINTR);
(void) close (parent_fd);
}
}
}
if (child_data->child_setup_func)
child_data->child_setup_func (child_data->child_setup_data);
}
#endif
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... */
}
#ifndef HAVE_O_CLOEXEC
else
fcntl (my_fd, F_SETFD, FD_CLOEXEC);
#endif
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);
g_object_unref (tasks->data);
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);
#ifdef G_OS_UNIX
ChildData child_data = { { -1, -1, -1 }, 0 };
#endif
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];
#ifdef G_OS_UNIX
else if (self->flags & G_SUBPROCESS_FLAGS_STDERR_MERGE)
/* This will work because stderr gets setup after stdout. */
child_data.fds[2] = 1;
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;
#ifdef G_OS_UNIX
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;
#endif
success = g_spawn_async_with_pipes (self->launcher ? self->launcher->cwd : NULL,
self->argv,
self->launcher ? self->launcher->envp : NULL,
spawn_flags,
#ifdef G_OS_UNIX
child_setup, &child_data,
#else
NULL, NULL,
#endif
&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 = g_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);
}
#ifdef G_OS_UNIX
out:
#endif
/* 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_strfreev (self->argv);
g_mutex_clear (&self->pending_waits_lock);
G_OBJECT_CLASS (g_subprocess_parent_class)->finalize (object);
}
static void
g_subprocess_init (GSubprocess *self)
{
g_mutex_init (&self->pending_waits_lock);
}
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)
* @flags: flags that define the behaviour of the subprocess
* @error: (nullable): return location for an error, or %NULL
* @argv0: first commandline argument to pass to the subprocess
* @...: more commandline arguments, followed by %NULL
*
* Create a new process with the given flags and varargs argument
* list. By default, matching the g_spawn_async() defaults, the
* child's stdin will be set to the system null device, and
* stdout/stderr will be inherited from the parent. You can use
* @flags to control this behavior.
*
* The argument list must be terminated with %NULL.
*
* Returns: A newly created #GSubprocess, or %NULL on error (and @error
* will be set)
*
* Since: 2.40
*/
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);
va_end (ap);
result = g_subprocess_newv ((const gchar * const *) args->pdata, flags, error);
g_ptr_array_free (args, TRUE);
return result;
}
/**
* g_subprocess_newv: (rename-to g_subprocess_new)
* @argv: (array zero-terminated=1) (element-type filename): commandline arguments for the subprocess
* @flags: flags that define the behaviour of the subprocess
* @error: (nullable): return location for an error, or %NULL
*
* 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: 2.40
*/
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);
}
/**
* g_subprocess_get_identifier:
* @subprocess: a #GSubprocess
*
* On UNIX, returns the process ID as a decimal string.
* On Windows, returns the result of GetProcessId() also as a string.
*/
const gchar *
g_subprocess_get_identifier (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), NULL);
if (subprocess->pid)
return subprocess->identifier;
else
return NULL;
}
/**
* g_subprocess_get_stdin_pipe:
* @subprocess: a #GSubprocess
*
* Gets the #GOutputStream that you can write to in order to give data
* to the stdin of @subprocess.
*
* The process must have been created with
* %G_SUBPROCESS_FLAGS_STDIN_PIPE.
*
* Returns: (transfer none): the stdout pipe
*
* Since: 2.40
**/
GOutputStream *
g_subprocess_get_stdin_pipe (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), NULL);
g_return_val_if_fail (subprocess->stdin_pipe, NULL);
return subprocess->stdin_pipe;
}
/**
* g_subprocess_get_stdout_pipe:
* @subprocess: a #GSubprocess
*
* Gets the #GInputStream from which to read the stdout output of
* @subprocess.
*
* The process must have been created with
* %G_SUBPROCESS_FLAGS_STDOUT_PIPE.
*
* Returns: (transfer none): the stdout pipe
*
* Since: 2.40
**/
GInputStream *
g_subprocess_get_stdout_pipe (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), NULL);
g_return_val_if_fail (subprocess->stdout_pipe, NULL);
return subprocess->stdout_pipe;
}
/**
* g_subprocess_get_stderr_pipe:
* @subprocess: a #GSubprocess
*
* Gets the #GInputStream from which to read the stderr output of
* @subprocess.
*
* The process must have been created with
* %G_SUBPROCESS_FLAGS_STDERR_PIPE.
*
* Returns: (transfer none): the stderr pipe
*
* Since: 2.40
**/
GInputStream *
g_subprocess_get_stderr_pipe (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), NULL);
g_return_val_if_fail (subprocess->stderr_pipe, NULL);
return subprocess->stderr_pipe;
}
/* Remove the first list element containing @data, and return %TRUE. If no
* such element is found, return %FALSE. */
static gboolean
slist_remove_if_present (GSList **list,
gconstpointer data)
{
GSList *l, *prev;
for (l = *list, prev = NULL; l != NULL; prev = l, l = prev->next)
{
if (l->data == data)
{
if (prev != NULL)
prev->next = l->next;
else
*list = l->next;
g_slist_free_1 (l);
return TRUE;
}
}
return FALSE;
}
static void
g_subprocess_wait_cancelled (GCancellable *cancellable,
gpointer user_data)
{
GTask *task = user_data;
GSubprocess *self;
gboolean task_was_pending;
self = g_task_get_source_object (task);
g_mutex_lock (&self->pending_waits_lock);
task_was_pending = slist_remove_if_present (&self->pending_waits, task);
g_mutex_unlock (&self->pending_waits_lock);
if (task_was_pending)
{
g_task_return_boolean (task, FALSE);
g_object_unref (task); /* ref from pending_waits */
}
}
/**
* g_subprocess_wait_async:
* @subprocess: a #GSubprocess
* @cancellable: a #GCancellable, or %NULL
* @callback: a #GAsyncReadyCallback to call when the operation is complete
* @user_data: user_data for @callback
*
* Wait for the subprocess to terminate.
*
* This is the asynchronous version of g_subprocess_wait().
*
* Since: 2.40
*/
void
g_subprocess_wait_async (GSubprocess *subprocess,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
task = g_task_new (subprocess, cancellable, callback, user_data);
g_task_set_source_tag (task, g_subprocess_wait_async);
g_mutex_lock (&subprocess->pending_waits_lock);
if (subprocess->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);
subprocess->pending_waits = g_slist_prepend (subprocess->pending_waits, task);
task = NULL;
}
g_mutex_unlock (&subprocess->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);
}
}
/**
* g_subprocess_wait_finish:
* @subprocess: a #GSubprocess
* @result: the #GAsyncResult passed to your #GAsyncReadyCallback
* @error: a pointer to a %NULL #GError, or %NULL
*
* Collects the result of a previous call to
* g_subprocess_wait_async().
*
* Returns: %TRUE if successful, or %FALSE with @error set
*
* Since: 2.40
*/
gboolean
g_subprocess_wait_finish (GSubprocess *subprocess,
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:
* @subprocess: a #GSubprocess
* @cancellable: a #GCancellable
* @error: a #GError
*
* Synchronously wait for the subprocess to terminate.
*
* After the process terminates you can query its exit status with
* functions such as g_subprocess_get_if_exited() and
* g_subprocess_get_exit_status().
*
* This function does not fail in the case of the subprocess having
* abnormal termination. See g_subprocess_wait_check() for that.
*
* Cancelling @cancellable doesn't kill the subprocess. Call
* g_subprocess_force_exit() if it is desirable.
*
* Returns: %TRUE on success, %FALSE if @cancellable was cancelled
*
* Since: 2.40
*/
gboolean
g_subprocess_wait (GSubprocess *subprocess,
GCancellable *cancellable,
GError **error)
{
GAsyncResult *result = NULL;
gboolean success;
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), 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 (subprocess->pid == 0)
return TRUE;
/* Otherwise, we need to do this the long way... */
g_subprocess_sync_setup ();
g_subprocess_wait_async (subprocess, cancellable, g_subprocess_sync_done, &result);
g_subprocess_sync_complete (&result);
success = g_subprocess_wait_finish (subprocess, result, error);
g_object_unref (result);
return success;
}
/**
* g_subprocess_wait_check:
* @subprocess: a #GSubprocess
* @cancellable: a #GCancellable
* @error: a #GError
*
* Combines g_subprocess_wait() with g_spawn_check_exit_status().
*
* Returns: %TRUE on success, %FALSE if process exited abnormally, or
* @cancellable was cancelled
*
* Since: 2.40
*/
gboolean
g_subprocess_wait_check (GSubprocess *subprocess,
GCancellable *cancellable,
GError **error)
{
return g_subprocess_wait (subprocess, cancellable, error) &&
g_spawn_check_exit_status (subprocess->status, error);
}
/**
* g_subprocess_wait_check_async:
* @subprocess: a #GSubprocess
* @cancellable: a #GCancellable, or %NULL
* @callback: a #GAsyncReadyCallback to call when the operation is complete
* @user_data: user_data for @callback
*
* Combines g_subprocess_wait_async() with g_spawn_check_exit_status().
*
* This is the asynchronous version of g_subprocess_wait_check().
*
* Since: 2.40
*/
void
g_subprocess_wait_check_async (GSubprocess *subprocess,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
g_subprocess_wait_async (subprocess, cancellable, callback, user_data);
}
/**
* g_subprocess_wait_check_finish:
* @subprocess: a #GSubprocess
* @result: the #GAsyncResult passed to your #GAsyncReadyCallback
* @error: a pointer to a %NULL #GError, or %NULL
*
* Collects the result of a previous call to
* g_subprocess_wait_check_async().
*
* Returns: %TRUE if successful, or %FALSE with @error set
*
* Since: 2.40
*/
gboolean
g_subprocess_wait_check_finish (GSubprocess *subprocess,
GAsyncResult *result,
GError **error)
{
return g_subprocess_wait_finish (subprocess, result, error) &&
g_spawn_check_exit_status (subprocess->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 *subprocess,
gint signalnum)
{
SignalRecord signal_record = { g_object_ref (subprocess), signalnum };
g_return_if_fail (G_IS_SUBPROCESS (subprocess));
/* 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:
* @subprocess: 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: 2.40
**/
void
g_subprocess_send_signal (GSubprocess *subprocess,
gint signal_num)
{
g_return_if_fail (G_IS_SUBPROCESS (subprocess));
g_subprocess_dispatch_signal (subprocess, signal_num);
}
#endif
/**
* g_subprocess_force_exit:
* @subprocess: 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: 2.40
**/
void
g_subprocess_force_exit (GSubprocess *subprocess)
{
g_return_if_fail (G_IS_SUBPROCESS (subprocess));
#ifdef G_OS_UNIX
g_subprocess_dispatch_signal (subprocess, SIGKILL);
#else
TerminateProcess (subprocess->pid, 1);
#endif
}
/**
* g_subprocess_get_status:
* @subprocess: 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: 2.40
**/
gint
g_subprocess_get_status (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE);
g_return_val_if_fail (subprocess->pid == 0, FALSE);
return subprocess->status;
}
/**
* g_subprocess_get_successful:
* @subprocess: 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: 2.40
**/
gboolean
g_subprocess_get_successful (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE);
g_return_val_if_fail (subprocess->pid == 0, FALSE);
#ifdef G_OS_UNIX
return WIFEXITED (subprocess->status) && WEXITSTATUS (subprocess->status) == 0;
#else
return subprocess->status == 0;
#endif
}
/**
* g_subprocess_get_if_exited:
* @subprocess: 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: 2.40
**/
gboolean
g_subprocess_get_if_exited (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE);
g_return_val_if_fail (subprocess->pid == 0, FALSE);
#ifdef G_OS_UNIX
return WIFEXITED (subprocess->status);
#else
return TRUE;
#endif
}
/**
* g_subprocess_get_exit_status:
* @subprocess: 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: 2.40
**/
gint
g_subprocess_get_exit_status (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), 1);
g_return_val_if_fail (subprocess->pid == 0, 1);
#ifdef G_OS_UNIX
g_return_val_if_fail (WIFEXITED (subprocess->status), 1);
return WEXITSTATUS (subprocess->status);
#else
return subprocess->status;
#endif
}
/**
* g_subprocess_get_if_signaled:
* @subprocess: 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: 2.40
**/
gboolean
g_subprocess_get_if_signaled (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), FALSE);
g_return_val_if_fail (subprocess->pid == 0, FALSE);
#ifdef G_OS_UNIX
return WIFSIGNALED (subprocess->status);
#else
return FALSE;
#endif
}
/**
* g_subprocess_get_term_sig:
* @subprocess: 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: 2.40
**/
gint
g_subprocess_get_term_sig (GSubprocess *subprocess)
{
g_return_val_if_fail (G_IS_SUBPROCESS (subprocess), 0);
g_return_val_if_fail (subprocess->pid == 0, 0);
#ifdef G_OS_UNIX
g_return_val_if_fail (WIFSIGNALED (subprocess->status), 0);
return WTERMSIG (subprocess->status);
#else
g_critical ("g_subprocess_get_term_sig() called on Windows, where "
"g_subprocess_get_if_signaled() always returns FALSE...");
return 0;
#endif
}
/*< 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;
gboolean add_nul;
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)
{
if (g_output_stream_splice_finish ((GOutputStream*) source, result, &error) == -1)
goto out;
if (source == state->stdout_buf ||
source == state->stderr_buf)
{
/* This is a memory stream, so it can't be cancelled or return
* an error really.
*/
if (state->add_nul)
{
gsize bytes_written;
if (!g_output_stream_write_all (source, "\0", 1, &bytes_written,
NULL, &error))
goto out;
}
if (!g_output_stream_close (source, NULL, &error))
goto out;
}
}
else if (source == subprocess)
{
(void) g_subprocess_wait_finish (subprocess, result, &error);
}
else
g_assert_not_reached ();
out:
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 (GCancellable *cancellable,
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->cancellable);
g_clear_object (&state->stdin_buf);
g_clear_object (&state->stdout_buf);
g_clear_object (&state->stderr_buf);
if (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,
gboolean add_nul,
GBytes *stdin_buf,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
CommunicateState *state;
GTask *task;
task = g_task_new (subprocess, cancellable, callback, user_data);
g_task_set_source_tag (task, g_subprocess_communicate_internal);
state = g_slice_new0 (CommunicateState);
g_task_set_task_data (task, state, g_subprocess_communicate_state_free);
state->cancellable = g_cancellable_new ();
state->add_nul = add_nul;
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_SOURCE_FUNC (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_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_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++;
g_object_unref (task);
return state;
}
/**
* g_subprocess_communicate:
* @subprocess: a #GSubprocess
* @stdin_buf: (nullable): data to send to the stdin of the subprocess, or %NULL
* @cancellable: a #GCancellable
* @stdout_buf: (out) (nullable) (optional) (transfer full): data read from the subprocess stdout
* @stderr_buf: (out) (nullable) (optional) (transfer full): 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_buf 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, FALSE, 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: (nullable): Input data, or %NULL
* @cancellable: (nullable): 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, FALSE, stdin_buf, cancellable, callback, user_data);
}
/**
* g_subprocess_communicate_finish:
* @subprocess: Self
* @result: Result
* @stdout_buf: (out) (nullable) (optional) (transfer full): Return location for stdout data
* @stderr_buf: (out) (nullable) (optional) (transfer full): 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 = (state->stdout_buf != NULL) ? g_memory_output_stream_steal_as_bytes (state->stdout_buf) : NULL;
if (stderr_buf)
*stderr_buf = (state->stderr_buf != NULL) ? g_memory_output_stream_steal_as_bytes (state->stderr_buf) : NULL;
}
g_object_unref (result);
return success;
}
/**
* g_subprocess_communicate_utf8:
* @subprocess: a #GSubprocess
* @stdin_buf: (nullable): data to send to the stdin of the subprocess, or %NULL
* @cancellable: a #GCancellable
* @stdout_buf: (out) (nullable) (optional) (transfer full): data read from the subprocess stdout
* @stderr_buf: (out) (nullable) (optional) (transfer full): data read from the subprocess stderr
* @error: a pointer to a %NULL #GError pointer, or %NULL
*
* Like g_subprocess_communicate(), but validates the output of the
* process as UTF-8, and returns it as a regular NUL terminated string.
*
* On error, @stdout_buf and @stderr_buf will be set to undefined values and
* should not be used.
*/
gboolean
g_subprocess_communicate_utf8 (GSubprocess *subprocess,
const char *stdin_buf,
GCancellable *cancellable,
char **stdout_buf,
char **stderr_buf,
GError **error)
{
GAsyncResult *result = NULL;
gboolean success;
GBytes *stdin_bytes;
size_t stdin_buf_len = 0;
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);
if (stdin_buf != NULL)
stdin_buf_len = strlen (stdin_buf);
stdin_bytes = g_bytes_new (stdin_buf, stdin_buf_len);
g_subprocess_sync_setup ();
g_subprocess_communicate_internal (subprocess, TRUE, stdin_bytes, cancellable,
g_subprocess_sync_done, &result);
g_subprocess_sync_complete (&result);
success = g_subprocess_communicate_utf8_finish (subprocess, result, stdout_buf, stderr_buf, error);
g_object_unref (result);
g_bytes_unref (stdin_bytes);
return success;
}
/**
* g_subprocess_communicate_utf8_async:
* @subprocess: Self
* @stdin_buf: (nullable): Input data, or %NULL
* @cancellable: Cancellable
* @callback: Callback
* @user_data: User data
*
* Asynchronous version of g_subprocess_communicate_utf8(). Complete
* invocation with g_subprocess_communicate_utf8_finish().
*/
void
g_subprocess_communicate_utf8_async (GSubprocess *subprocess,
const char *stdin_buf,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GBytes *stdin_bytes;
size_t stdin_buf_len = 0;
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));
if (stdin_buf != NULL)
stdin_buf_len = strlen (stdin_buf);
stdin_bytes = g_bytes_new (stdin_buf, stdin_buf_len);
g_subprocess_communicate_internal (subprocess, TRUE, stdin_bytes, cancellable, callback, user_data);
g_bytes_unref (stdin_bytes);
}
static gboolean
communicate_result_validate_utf8 (const char *stream_name,
char **return_location,
GMemoryOutputStream *buffer,
GError **error)
{
if (return_location == NULL)
return TRUE;
if (buffer)
{
const char *end;
*return_location = g_memory_output_stream_steal_data (buffer);
if (!g_utf8_validate (*return_location, -1, &end))
{
g_free (*return_location);
*return_location = NULL;
g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
"Invalid UTF-8 in child %s at offset %lu",
stream_name,
(unsigned long) (end - *return_location));
return FALSE;
}
}
else
*return_location = NULL;
return TRUE;
}
/**
* g_subprocess_communicate_utf8_finish:
* @subprocess: Self
* @result: Result
* @stdout_buf: (out) (nullable) (optional) (transfer full): Return location for stdout data
* @stderr_buf: (out) (nullable) (optional) (transfer full): Return location for stderr data
* @error: Error
*
* Complete an invocation of g_subprocess_communicate_utf8_async().
*/
gboolean
g_subprocess_communicate_utf8_finish (GSubprocess *subprocess,
GAsyncResult *result,
char **stdout_buf,
char **stderr_buf,
GError **error)
{
gboolean ret = FALSE;
CommunicateState *state;
gchar *local_stdout_buf = NULL, *local_stderr_buf = NULL;
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);
if (!g_task_propagate_boolean ((GTask*)result, error))
goto out;
/* TODO - validate UTF-8 while streaming, rather than all at once.
*/
if (!communicate_result_validate_utf8 ("stdout", &local_stdout_buf,
state->stdout_buf,
error))
goto out;
if (!communicate_result_validate_utf8 ("stderr", &local_stderr_buf,
state->stderr_buf,
error))
goto out;
ret = TRUE;
out:
g_object_unref (result);
if (ret && stdout_buf != NULL)
*stdout_buf = g_steal_pointer (&local_stdout_buf);
if (ret && stderr_buf != NULL)
*stderr_buf = g_steal_pointer (&local_stderr_buf);
g_free (local_stderr_buf);
g_free (local_stdout_buf);
return ret;
}
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