Subprocess

gio.Subprocess allows the creation of and interaction with child processes.

Processes can be communicated with using standard GIO-style APIs (ie: gio.InputStream, 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 OutputStream.spliceAsync. 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 gio.Subprocess 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 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.

gio.Subprocess 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 gio.Subprocess API (unless G_SUBPROCESS_FLAGS_INHERIT_FDS was specified).

gio.Subprocess will quickly reap all child processes as they exit, avoiding "zombie processes" remaining around for long periods of time. 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, gio.Subprocess 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.

gio.Subprocess 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 Subprocess.new. The 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 gio.Subprocess will involve calling Subprocess.new, followed by Subprocess.waitAsync or Subprocess.wait. After the process exits, the status can be checked using functions such as Subprocess.getIfExited (which are similar to the familiar WIFEXITED-style POSIX macros).

Constructors

this
this(GSubprocess* gSubprocess, bool ownedRef = false)

Sets our main struct and passes it to the parent class.

this
this(string[] argv, GSubprocessFlags flags)

Create a new process with the given flags and argument list.

Members

Functions

communicate
bool communicate(Bytes stdinBuf, Cancellable cancellable, out Bytes stdoutBuf, out Bytes stderrBuf)

Communicate with the subprocess until it terminates, and all input and output has been completed.

communicateAsync
void communicateAsync(Bytes stdinBuf, Cancellable cancellable, GAsyncReadyCallback callback, void* userData)

Asynchronous version of Subprocess.communicate. Complete invocation with Subprocess.communicateFinish.

communicateFinish
bool communicateFinish(AsyncResultIF result, out Bytes stdoutBuf, out Bytes stderrBuf)

Complete an invocation of Subprocess.communicateAsync.

communicateUtf8
bool communicateUtf8(string stdinBuf, Cancellable cancellable, out string stdoutBuf, out string stderrBuf)

Like Subprocess.communicate, but validates the output of the process as UTF-8, and returns it as a regular NUL terminated string.

communicateUtf8Async
void communicateUtf8Async(string stdinBuf, Cancellable cancellable, GAsyncReadyCallback callback, void* userData)

Asynchronous version of Subprocess.communicateUtf8. Complete invocation with Subprocess.communicateUtf8Finish.

communicateUtf8Finish
bool communicateUtf8Finish(AsyncResultIF result, out string stdoutBuf, out string stderrBuf)

Complete an invocation of Subprocess.communicateUtf8Async.

forceExit
void forceExit()

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 Subprocess.wait to monitor the status of the process after calling this function.

getExitStatus
int getExitStatus()

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.

getIdentifier
string getIdentifier()

On UNIX, returns the process ID as a decimal string. On Windows, returns the result of GetProcessId() also as a string.

getIfExited
bool getIfExited()

Check if the given subprocess exited normally (ie: by way of exit() or return from main()).

getIfSignaled
bool getIfSignaled()

Check if the given subprocess terminated in response to a signal.

getStatus
int getStatus()

Gets the raw status code of the process, as from waitpid().

getStderrPipe
InputStream getStderrPipe()

Gets the gio.InputStream from which to read the stderr output of subprocess.

getStdinPipe
OutputStream getStdinPipe()

Gets the gio.OutputStream that you can write to in order to give data to the stdin of subprocess.

getStdoutPipe
InputStream getStdoutPipe()

Gets the gio.InputStream from which to read the stdout output of subprocess.

getStruct
void* getStruct()

the main Gtk struct as a void*

getSubprocessStruct
GSubprocess* getSubprocessStruct(bool transferOwnership = false)

Get the main Gtk struct

getSuccessful
bool getSuccessful()

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().

getTermSig
int getTermSig()

Get the signal number that caused the subprocess to terminate, given that it terminated due to a signal.

sendSignal
void sendSignal(int signalNum)

Sends the UNIX signal signal_num to the subprocess, if it is still running.

wait
bool wait(Cancellable cancellable)

Synchronously wait for the subprocess to terminate.

waitAsync
void waitAsync(Cancellable cancellable, GAsyncReadyCallback callback, void* userData)

Wait for the subprocess to terminate.

waitCheck
bool waitCheck(Cancellable cancellable)

Combines Subprocess.wait with Spawn.checkExitStatus.

waitCheckAsync
void waitCheckAsync(Cancellable cancellable, GAsyncReadyCallback callback, void* userData)

Combines Subprocess.waitAsync with Spawn.checkExitStatus.

waitCheckFinish
bool waitCheckFinish(AsyncResultIF result)

Collects the result of a previous call to Subprocess.waitCheckAsync.

waitFinish
bool waitFinish(AsyncResultIF result)

Collects the result of a previous call to Subprocess.waitAsync.

Static functions

getType
GType getType()

Variables

gSubprocess
GSubprocess* gSubprocess;

the main Gtk struct

Inherited Members

From ObjectG

gObject
GObject* gObject;

the main Gtk struct

getObjectGStruct
GObject* getObjectGStruct(bool transferOwnership = false)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

opCast
T opCast()
getDObject
RT getDObject(U obj, bool ownedRef = false)

Gets a D Object from the objects table of associations.

setProperty
void setProperty(string propertyName, T value)
addOnNotify
gulong addOnNotify(void delegate(ParamSpec, ObjectG) dlg, string property = "", ConnectFlags connectFlags = cast(ConnectFlags)0)

The notify signal is emitted on an object when one of its properties has been changed. Note that getting this signal doesn't guarantee that the value of the property has actually changed, it may also be emitted when the setter for the property is called to reinstate the previous value.

getType
GType getType()
compatControl
size_t compatControl(size_t what, void* data)
interfaceFindProperty
ParamSpec interfaceFindProperty(TypeInterface gIface, string propertyName)

Find the gobject.ParamSpec with the given name for an interface. Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

interfaceInstallProperty
void interfaceInstallProperty(TypeInterface gIface, ParamSpec pspec)

Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created gobject.ParamSpec, but normally ObjectClass.overrideProperty will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.

interfaceListProperties
ParamSpec[] interfaceListProperties(TypeInterface gIface)

Lists the properties of an interface.Generally, the interface vtable passed in as g_iface will be the default vtable from g_type_default_interface_ref(), or, if you know the interface has already been loaded, g_type_default_interface_peek().

addToggleRef
void addToggleRef(GToggleNotify notify, void* data)

Increases the reference count of the object by one and sets a callback to be called when all other references to the object are dropped, or when this is already the last reference to the object and another reference is established.

addWeakPointer
void addWeakPointer(ref void* weakPointerLocation)

Adds a weak reference from weak_pointer to object to indicate that the pointer located at weak_pointer_location is only valid during the lifetime of object. When the object is finalized, weak_pointer will be set to NULL.

bindProperty
Binding bindProperty(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags)

Creates a binding between source_property on source and target_property on target. Whenever the source_property is changed the target_property is updated using the same value. For instance:

bindPropertyFull
Binding bindPropertyFull(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, GBindingTransformFunc transformTo, GBindingTransformFunc transformFrom, void* userData, GDestroyNotify notify)

Complete version of g_object_bind_property().

bindPropertyWithClosures
Binding bindPropertyWithClosures(string sourceProperty, ObjectG target, string targetProperty, GBindingFlags flags, Closure transformTo, Closure transformFrom)

Creates a binding between source_property on source and target_property on target, allowing you to set the transformation functions to be used by the binding.

dupData
void* dupData(string key, GDuplicateFunc dupFunc, void* userData)

This is a variant of g_object_get_data() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.

dupQdata
void* dupQdata(GQuark quark, GDuplicateFunc dupFunc, void* userData)

This is a variant of g_object_get_qdata() which returns a 'duplicate' of the value. dup_func defines the meaning of 'duplicate' in this context, it could e.g. take a reference on a ref-counted object.

forceFloating
void forceFloating()

This function is intended for GObject implementations to re-enforce a floating[floating-ref] object reference. Doing this is seldom required: all GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling g_object_ref_sink().

freezeNotify
void freezeNotify()

Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one notify signal is emitted for each property modified while the object is frozen.

getData
void* getData(string key)

Gets a named field from the objects table of associations (see g_object_set_data()).

getProperty
void getProperty(string propertyName, Value value)

Gets a property of an object. value must have been initialized to the expected type of the property (or a type to which the expected type can be transformed) using Value.init.

getQdata
void* getQdata(GQuark quark)

This function gets back user data pointers stored via g_object_set_qdata().

getValist
void getValist(string firstPropertyName, void* varArgs)

Gets properties of an object.

getv
void getv(string[] names, Value[] values)

Gets n_properties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

isFloating
bool isFloating()

Checks whether object has a floating[floating-ref] reference.

notify
void notify(string propertyName)

Emits a "notify" signal for the property property_name on object.

notifyByPspec
void notifyByPspec(ParamSpec pspec)

Emits a "notify" signal for the property specified by pspec on object.

doref
ObjectG doref()

Increases the reference count of object.

refSink
ObjectG refSink()

Increase the reference count of object, and possibly remove the floating[floating-ref] reference, if object has a floating reference.

removeToggleRef
void removeToggleRef(GToggleNotify notify, void* data)

Removes a reference added with g_object_add_toggle_ref(). The reference count of the object is decreased by one.

removeWeakPointer
void removeWeakPointer(ref void* weakPointerLocation)

Removes a weak reference from object that was previously added using g_object_add_weak_pointer(). The weak_pointer_location has to match the one used with g_object_add_weak_pointer().

replaceData
bool replaceData(string key, void* oldval, void* newval, GDestroyNotify destroy, out GDestroyNotify oldDestroy)

Compares the user data for the key key on object with oldval, and if they are the same, replaces oldval with newval.

replaceQdata
bool replaceQdata(GQuark quark, void* oldval, void* newval, GDestroyNotify destroy, out GDestroyNotify oldDestroy)

Compares the user data for the key quark on object with oldval, and if they are the same, replaces oldval with newval.

runDispose
void runDispose()

Releases all references to other objects. This can be used to break reference cycles.

setData
void setData(string key, void* data)

Each object carries around a table of associations from strings to pointers. This function lets you set an association.

setDataFull
void setDataFull(string key, void* data, GDestroyNotify destroy)

Like g_object_set_data() except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.

setProperty
void setProperty(string propertyName, Value value)

Sets a property on an object.

setQdata
void setQdata(GQuark quark, void* data)

This sets an opaque, named pointer on an object. The name is specified through a GQuark (retrived e.g. via g_quark_from_static_string()), and the pointer can be gotten back from the object with g_object_get_qdata() until the object is finalized. Setting a previously set user data pointer, overrides (frees) the old pointer set, using NULL as pointer essentially removes the data stored.

setQdataFull
void setQdataFull(GQuark quark, void* data, GDestroyNotify destroy)

This function works like g_object_set_qdata(), but in addition, a void (*destroy) (gpointer) function may be specified which is called with data as argument when the object is finalized, or the data is being overwritten by a call to g_object_set_qdata() with the same quark.

setValist
void setValist(string firstPropertyName, void* varArgs)

Sets properties on an object.

setv
void setv(string[] names, Value[] values)

Sets n_properties properties for an object. Properties to be set will be taken from values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

stealData
void* stealData(string key)

Remove a specified datum from the object's data associations, without invoking the association's destroy handler.

stealQdata
void* stealQdata(GQuark quark)

This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:

thawNotify
void thawNotify()

Reverts the effect of a previous call to g_object_freeze_notify(). The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.

unref
void unref()

Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).

watchClosure
void watchClosure(Closure closure)

This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling Closure.invalidate on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, g_object_ref() and g_object_unref() are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.

weakRef
void weakRef(GWeakNotify notify, void* data)

Adds a weak reference callback to an object. Weak references are used for notification when an object is finalized. They are called "weak references" because they allow you to safely hold a pointer to an object without calling g_object_ref() (g_object_ref() adds a strong reference, that is, forces the object to stay alive).

weakUnref
void weakUnref(GWeakNotify notify, void* data)

Removes a weak reference callback to an object.

clearObject
void clearObject(ref ObjectG objectPtr)

Clears a reference to a GObject

From InitableIF

getInitableStruct
GInitable* getInitableStruct(bool transferOwnership = false)

Get the main Gtk struct

getStruct
void* getStruct()

the main Gtk struct as a void*

getType
GType getType()
init
bool init(Cancellable cancellable)

Initializes the object implementing the interface.

Meta

Since

2.40