Subprocess
GSubprocess allows the creation of and interaction with child processes.
Processes can be communicated with using standard GIO-style APIs (ie: class@Gio.InputStream, class@Gio.OutputStream). 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 method@Gio.OutputStream.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 method@Gio.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. method@Gio.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. By default, the PATH of the current process is used. You can specify G_SUBPROCESS_FLAGS_SEARCH_PATH_FROM_ENVP to use the PATH of the launcher environment instead.
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 ctor@Gio.Subprocess.new. The class@Gio.SubprocessLauncher 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 ctor@Gio.Subprocess.new, followed by method@Gio.Subprocess.wait_async or method@Gio.Subprocess.wait. After the process exits, the status can be checked using functions such as method@Gio.Subprocess.get_if_exited (which are similar to the familiar WIFEXITED-style POSIX macros).
Note that as of GLib 2.82, creating a GSubprocess causes the signal SIGPIPE to be ignored for the remainder of the program. If you are writing a command-line utility that uses GSubprocess, you may need to take into account the fact that your program will not automatically be killed if it tries to write to stdout after it has been closed.
Skipped during bindings generation
parameter
stdout_buf: stdout_buf: Out parameter is not supportedparameter
stdout_buf: stdout_buf: Out parameter is not supportedparameter
stdout_buf: stdout_buf: Out parameter is not supportedparameter
stdout_buf: stdout_buf: Out parameter is not supportedmethod
argv: Property has no getter nor settermethod
flags: Property has no getter nor setter
Since
2.40
Constructors
Functions
Asynchronous version of g_subprocess_communicate(). Complete invocation with g_subprocess_communicate_finish().
Asynchronous version of g_subprocess_communicate_utf8(). Complete invocation with g_subprocess_communicate_utf8_finish().
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.
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.
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.
Check if the given subprocess exited normally (ie: by way of exit() or return from main()).
Check if the given subprocess terminated in response to a signal.
Gets the #GInputStream from which to read the stderr output of
Gets the #GOutputStream that you can write to in order to give data to the stdin of @subprocess.
Gets the #GInputStream from which to read the stdout output of
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().
Get the signal number that caused the subprocess to terminate, given that it terminated due to a signal.
Initializes the object implementing the interface.
Sends the UNIX signal @signal_num to the subprocess, if it is still running.
Synchronously wait for the subprocess to terminate.
Wait for the subprocess to terminate.
Combines g_subprocess_wait() with g_spawn_check_wait_status().
Combines g_subprocess_wait_async() with g_spawn_check_wait_status().
Collects the result of a previous call to g_subprocess_wait_check_async().
Collects the result of a previous call to g_subprocess_wait_async().