ApplicationCommandLine

gio.ApplicationCommandLine represents a command-line invocation of an application. It is created by gtk.Application and emitted in the command-line signal and virtual function.

The class contains the list of arguments that the program was invoked with. It is also possible to query if the commandline invocation was local (ie: the current process is running in direct response to the invocation) or remote (ie: some other process forwarded the commandline to this process).

The GApplicationCommandLine object can provide the argc and argv parameters for use with the glib.OptionContext command-line parsing API, with the Application.commandLineGetArguments function. See [gapplication-example-cmdline3.c][gapplication-example-cmdline3] for an example.

The exit status of the originally-invoked process may be set and messages can be printed to stdout or stderr of that process. The lifecycle of the originally-invoked process is tied to the lifecycle of this object (ie: the process exits when the last reference is dropped).

The main use for gio.ApplicationCommandLine (and the command-line signal) is 'Emacs server' like use cases: You can set the EDITOR environment variable to have e.g. git use your favourite editor to edit commit messages, and if you already have an instance of the editor running, the editing will happen in the running instance, instead of opening a new one. An important aspect of this use case is that the process that gets started by git does not return until the editing is done.

Normally, the commandline is completely handled in the command-line handler. The launching instance exits once the signal handler in the primary instance has returned, and the return value of the signal handler becomes the exit status of the launching instance.

static int
command_line (GApplication            *application,
GApplicationCommandLine *cmdline)
{
gchar **argv;
gint argc;
gint i;

argv = g_application_command_line_get_arguments (cmdline, &argc);

g_application_command_line_print (cmdline,
"This text is written back\n"
"to stdout of the caller\n");

for (i = 0; i < argc; i++)
g_print ("argument `d:` `s`\n", i, argv[i]);

g_strfreev (argv);

return 0;
}

he complete example can be found here: gapplication-example-cmdline.c

In more complicated cases, the handling of the comandline can be split between the launcher and the primary instance.

static gboolean
test_local_cmdline (GApplication   *application,
gchar        ***arguments,
gint           *exit_status)
{
gint i, j;
gchar **argv;

argv = *arguments;

i = 1;
while (argv[i])
{
if (g_str_has_prefix (argv[i], "--local-"))
{
g_print ("handling argument `s` locally\n", argv[i]);
g_free (argv[i]);
for (j = i; argv[j]; j++)
argv[j] = argv[j + 1];
}
else
{
g_print ("not handling argument `s` locally\n", argv[i]);
i++;
}
}

*exit_status = 0;

return FALSE;
}

static void
test_application_class_init (TestApplicationClass *class)
{
G_APPLICATION_CLASS (class)->local_command_line = test_local_cmdline;

...
}

n this example of split commandline handling, options that start with --local- are handled locally, all other options are passed to the command-line handler which runs in the primary instance.

The complete example can be found here: gapplication-example-cmdline2.c

If handling the commandline requires a lot of work, it may be better to defer it.

static gboolean
my_cmdline_handler (gpointer data)
{
GApplicationCommandLine *cmdline = data;

// do the heavy lifting in an idle

g_application_command_line_set_exit_status (cmdline, 0);
g_object_unref (cmdline); // this releases the application

return G_SOURCE_REMOVE;
}

static int
command_line (GApplication            *application,
GApplicationCommandLine *cmdline)
{
// keep the application running until we are done with this commandline
g_application_hold (application);

g_object_set_data_full (G_OBJECT (cmdline),
"application", application,
(GDestroyNotify)g_application_release);

g_object_ref (cmdline);
g_idle_add (my_cmdline_handler, cmdline);

return 0;
}

n this example the commandline is not completely handled before the command-line handler returns. Instead, we keep a reference to the gio.ApplicationCommandLine object and handle it later (in this example, in an idle). Note that it is necessary to hold the application until you are done with the commandline.

The complete example can be found here: gapplication-example-cmdline3.c

class ApplicationCommandLine : ObjectG {

protected

GApplicationCommandLine* gApplicationCommandLine;

GApplicationCommandLine* getApplicationCommandLineStruct(bool transferOwnership);

void* getStruct();

this(GApplicationCommandLine* gApplicationCommandLine, bool ownedRef);

static GType getType();

FileIF createFileForArg(string arg);

string[] getArguments();

string getCwd();

string[] getEnviron();

int getExitStatus();

bool getIsRemote();

VariantDict getOptionsDict();

Variant getPlatformData();

InputStream getStdin();

string getenv(string name);

void setExitStatus(int exitStatus);

}

Constructors

this this(GApplicationCommandLine* gApplicationCommandLine, bool ownedRef): Sets our main struct and passes it to the parent class.

Members

Functions

createFileForArg FileIF createFileForArg(string arg): Creates a GFile corresponding to a filename that was given as part of the invocation of cmdline.
getApplicationCommandLineStruct GApplicationCommandLine* getApplicationCommandLineStruct(bool transferOwnership): Get the main Gtk struct
getArguments string[] getArguments(): Gets the list of arguments that was passed on the command line.
getCwd string getCwd(): Gets the working directory of the command line invocation. The string may contain non-utf8 data.
getEnviron string[] getEnviron(): Gets the contents of the 'environ' variable of the command line invocation, as would be returned by g_get_environ(), ie as a NULL-terminated list of strings in the form 'NAME=VALUE'. The strings may contain non-utf8 data.
getExitStatus int getExitStatus(): Gets the exit status of cmdline. See Application.commandLineSetExitStatus for more information.
getIsRemote bool getIsRemote(): Determines if cmdline represents a remote invocation.
getOptionsDict VariantDict getOptionsDict(): Gets the options there were passed to Application.commandLine.
getPlatformData Variant getPlatformData(): Gets the platform data associated with the invocation of cmdline.
getStdin InputStream getStdin(): Gets the stdin of the invoking process.
getStruct void* getStruct(): the main Gtk struct as a void*
getenv string getenv(string name): Gets the value of a particular environment variable of the command line invocation, as would be returned by g_getenv(). The strings may contain non-utf8 data.
setExitStatus void setExitStatus(int exitStatus): Sets the exit status that will be used when the invoking process exits.

Static functions

getType GType getType()

Variables

gApplicationCommandLine GApplicationCommandLine* gApplicationCommandLine;: the main Gtk struct

Inherited Members

From ObjectG

gObject GObject* gObject;: the main Gtk struct
getObjectGStruct GObject* getObjectGStruct(bool transferOwnership): 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): 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): 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(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.
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.
ref_ ObjectG ref_(): 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(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, 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, 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(ObjectG objectPtr): Clears a reference to a GObject

gio ApplicationCommandLine classes