luc14n0/glib
1
0
Fork 0
mirror of https://gitlab.gnome.org/GNOME/glib.git synced 2024-11-15 05:46:15 +01:00
Code Issues Packages Projects Releases Wiki Activity
375cbee175
glib/gio/gsubprocess.c
Alexander Larsson 4cf95e3904 Ensure g_subprocess_communicate_async() never blocks 
It turns out that our async write operation implementation is broken
on non-O_NONBLOCK pipes, because the default async write
implementation calls write() after poll() said there were some
space. However, the semantics of pipes is that unless O_NONBLOCK is set
then the write *will* block if the passed in write count is larger than
the available space.

This caused a deadlock in https://gitlab.gnome.org/GNOME/glib/-/issues/2182
due to the loop-back of the app stdout to the parent, but even without such
a deadlock it is a problem that we may block the mainloop at all.

In the particular case of g_subprocess_communicate() we have full
control of the pipes after starting the app, so it is safe to enable
O_NONBLOCK (i.e. we can ensure all the code using the fd after this can handle
non-blocking mode).

This fixes https://gitlab.gnome.org/GNOME/glib/-/issues/2182
2020-08-17 12:57:24 +02:00

1966 lines
60 KiB
C
Raw Blame History

/* 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 G_GNUC_UNUSED /* when compiling with G_DISABLE_ASSERT */;
#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.
* If the subprocess has terminated, this will return %NULL.
*
* Returns: (nullable): the subprocess identifier, or %NULL if the subprocess
* has terminated
* Since: 2.40
*/
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);
#ifdef G_OS_UNIX
/* We're doing async writes to the pipe, and the async write mechanism assumes
* that streams polling as writable do SOME progress (possibly partial) and then
* stop, but never block.
*
* However, for blocking pipes, unix will return writable if there is *any* space left
* but still block until the full buffer size is available before returning from write.
* So, to avoid async blocking on the main loop we make this non-blocking here.
*
* It should be safe to change the fd because we're the only user at this point as
* per the g_subprocess_communicate() docs, and all the code called by this function
* properly handles non-blocking fds.
*/
g_unix_set_fd_nonblocking (g_unix_output_stream_get_fd (G_UNIX_OUTPUT_STREAM (subprocess->stdin_pipe)), TRUE, NULL);
#endif
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;
}
Reference in New Issue View Git Blame Copy Permalink