Struct gio::ApplicationCommandLine

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pub struct ApplicationCommandLine { /* private fields */ }
Expand description

GApplicationCommandLine represents a command-line invocation of an application.

It is created by 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 ApplicationCommandLineExt::arguments() 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.

For remote invocation, the originally-invoked process exits when ApplicationCommandLineExt::done() method is called. This method is also automatically called when the object is disposed.

The main use for GApplicationCommandLine (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.

⚠️ The following code is in c ⚠️

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;
}

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

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

⚠️ The following code is in c ⚠️

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

  argv = *arguments;

  if (argv[0] == NULL)
    {
      *exit_status = 0;
      return FALSE;
    }

  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;

  ...
}

In 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.

⚠️ The following code is in c ⚠️

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;
}

In this example the commandline is not completely handled before the command-line handler returns. Instead, we keep a reference to the GApplicationCommandLine 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

§Properties

§arguments

The commandline that caused this command-line signal emission.

Writeable | Construct Only

§is-remote

Whether this is a remote commandline.

Readable

§options

The options sent along with the commandline.

Writeable | Construct Only

§platform-data

Platform-specific data for the commandline.

Writeable | Construct Only

§Implements

ApplicationCommandLineExt, [trait@glib::ObjectExt]

GLib type: GObject with reference counted clone semantics.

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Trait Implementations§

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impl Clone for ApplicationCommandLine

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fn clone(&self) -> Self

Makes a clone of this shared reference.

This increments the strong reference count of the object. Dropping the object will decrement it again.

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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for ApplicationCommandLine

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fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
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impl HasParamSpec for ApplicationCommandLine

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type ParamSpec = ParamSpecObject

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type SetValue = ApplicationCommandLine

Preferred value to be used as setter for the associated ParamSpec.
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type BuilderFn = fn(_: &str) -> ParamSpecObjectBuilder<'_, ApplicationCommandLine>

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fn param_spec_builder() -> Self::BuilderFn

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impl Hash for ApplicationCommandLine

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fn hash<H>(&self, state: &mut H)
where H: Hasher,

Hashes the memory address of this object.

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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl Ord for ApplicationCommandLine

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fn cmp(&self, other: &Self) -> Ordering

Comparison for two GObjects.

Compares the memory addresses of the provided objects.

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fn max(self, other: Self) -> Self
where Self: Sized,

Compares and returns the maximum of two values. Read more
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fn min(self, other: Self) -> Self
where Self: Sized,

Compares and returns the minimum of two values. Read more
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fn clamp(self, min: Self, max: Self) -> Self
where Self: Sized + PartialOrd,

Restrict a value to a certain interval. Read more
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impl ParentClassIs for ApplicationCommandLine

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impl<OT: ObjectType> PartialEq<OT> for ApplicationCommandLine

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fn eq(&self, other: &OT) -> bool

Equality for two GObjects.

Two GObjects are equal if their memory addresses are equal.

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fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl<OT: ObjectType> PartialOrd<OT> for ApplicationCommandLine

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fn partial_cmp(&self, other: &OT) -> Option<Ordering>

Partial comparison for two GObjects.

Compares the memory addresses of the provided objects.

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fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator. Read more
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fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more
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fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator. Read more
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fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more
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impl StaticType for ApplicationCommandLine

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fn static_type() -> Type

Returns the type identifier of Self.
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impl Eq for ApplicationCommandLine

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<O> ApplicationCommandLineExt for O

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fn create_file_for_arg(&self, arg: impl AsRef<OsStr>) -> File

Creates a #GFile corresponding to a filename that was given as part of the invocation of @self. Read more
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fn done(&self)

Available on crate feature v2_80 only.
Signals that command line processing is completed. Read more
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fn arguments(&self) -> Vec<OsString>

Gets the list of arguments that was passed on the command line. Read more
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fn cwd(&self) -> Option<PathBuf>

Gets the working directory of the command line invocation. The string may contain non-utf8 data. Read more
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fn environ(&self) -> Vec<OsString>

Gets the contents of the ‘environ’ variable of the command line invocation, as would be returned by g_get_environ(), ie as a None-terminated list of strings in the form ‘NAME=VALUE’. The strings may contain non-utf8 data. Read more
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fn exit_status(&self) -> i32

Gets the exit status of @self. See g_application_command_line_set_exit_status() for more information. Read more
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fn is_remote(&self) -> bool

Determines if @self represents a remote invocation. Read more
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fn options_dict(&self) -> VariantDict

Gets the options that were passed to g_application_command_line(). Read more
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fn platform_data(&self) -> Option<Variant>

Gets the platform data associated with the invocation of @self. Read more
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fn stdin(&self) -> Option<InputStream>

Gets the stdin of the invoking process. Read more
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fn getenv(&self, name: impl AsRef<OsStr>) -> Option<GString>

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. Read more
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fn print_literal(&self, message: &str)

Available on crate feature v2_80 only.
Prints a message using the stdout print handler in the invoking process. Read more
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fn printerr_literal(&self, message: &str)

Available on crate feature v2_80 only.
Prints a message using the stderr print handler in the invoking process. Read more
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fn set_exit_status(&self, exit_status: i32)

Sets the exit status that will be used when the invoking process exits. Read more
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fn connect_is_remote_notify<F: Fn(&Self) + 'static>( &self, f: F, ) -> SignalHandlerId

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impl<T> Borrow<T> for T
where T: ?Sized,

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Immutably borrows from an owned value. Read more
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Upcasts an object to a reference of its superclass or interface T. Read more
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Tries to downcast to a subclass or interface implementor T. Read more
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Tries to downcast to a reference of its subclass or interface implementor T. Read more
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Tries to cast to an object of type T. This handles upcasting, downcasting and casting between interface and interface implementors. All checks are performed at runtime, while upcast will do many checks at compile-time already. downcast will perform the same checks at runtime as dynamic_cast, but will also ensure some amount of compile-time safety. Read more
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Casts to T unconditionally. Read more
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default unsafe fn clone_to_uninit(&self, dst: *mut T)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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where U: From<T>,

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Calls U::from(self).

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Sets multiple properties of the object at once. Read more
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Check if the object has a property property_name of the given type_. Read more
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Get the type of the property property_name of this object. Read more
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Get the ParamSpec of the property property_name of this object.
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Return all ParamSpec of the properties of this object.
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fn freeze_notify(&self) -> PropertyNotificationFreezeGuard

Freeze all property notifications until the return guard object is dropped. Read more
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unsafe fn set_qdata<QD>(&self, key: Quark, value: QD)
where QD: 'static,

Set arbitrary data on this object with the given key. Read more
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Retrieve previously set arbitrary data of this object with the given key. Read more
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where QD: 'static,

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where QD: 'static,

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where QD: 'static,

Retrieve previously set arbitrary data of this object with the given key. Read more
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fn block_signal(&self, handler_id: &SignalHandlerId)

Block a given signal handler. Read more
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fn unblock_signal(&self, handler_id: &SignalHandlerId)

Unblock a given signal handler.
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fn stop_signal_emission(&self, signal_id: SignalId, detail: Option<Quark>)

Stop emission of the currently emitted signal.
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fn stop_signal_emission_by_name(&self, signal_name: &str)

Stop emission of the currently emitted signal by the (possibly detailed) signal name.
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fn connect<F>( &self, signal_name: &str, after: bool, callback: F, ) -> SignalHandlerId
where F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static,

Connect to the signal signal_name on this object. Read more
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where F: Fn(&[Value]) -> Option<Value> + Send + Sync + 'static,

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where F: Fn(&[Value]) -> Option<Value> + 'static,

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where F: Fn(&[Value]) -> Option<Value> + 'static,

Connect to the signal signal_id on this object. Read more
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unsafe fn connect_unsafe<F>( &self, signal_name: &str, after: bool, callback: F, ) -> SignalHandlerId
where F: Fn(&[Value]) -> Option<Value>,

Connect to the signal signal_name on this object. Read more
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unsafe fn connect_unsafe_id<F>( &self, signal_id: SignalId, details: Option<Quark>, after: bool, callback: F, ) -> SignalHandlerId
where F: Fn(&[Value]) -> Option<Value>,

Connect to the signal signal_id on this object. Read more
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Connect a closure to the signal signal_name on this object. Read more
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Connect a closure to the signal signal_id on this object. Read more
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fn watch_closure(&self, closure: &impl AsRef<Closure>)

Limits the lifetime of closure to the lifetime of the object. When the object’s reference count drops to zero, the closure will be invalidated. An invalidated closure will ignore any calls to invoke_with_values, or invoke when using Rust closures.
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fn emit<R>(&self, signal_id: SignalId, args: &[&dyn ToValue]) -> R

Emit signal by signal id. Read more
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Same as Self::emit but takes Value for the arguments.
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Emit signal by its name. Read more
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Emit signal by its name. Read more
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Emit signal by its name with details. Read more
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Emit signal by its name with details. Read more
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Emit signal by signal id with details. Read more
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Emit signal by signal id with details. Read more
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fn disconnect(&self, handler_id: SignalHandlerId)

Disconnect a previously connected signal handler.
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fn connect_notify<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId
where F: Fn(&T, &ParamSpec) + Send + Sync + 'static,

Connect to the notify signal of the object. Read more
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fn connect_notify_local<F>(&self, name: Option<&str>, f: F) -> SignalHandlerId
where F: Fn(&T, &ParamSpec) + 'static,

Connect to the notify signal of the object. Read more
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unsafe fn connect_notify_unsafe<F>( &self, name: Option<&str>, f: F, ) -> SignalHandlerId
where F: Fn(&T, &ParamSpec),

Connect to the notify signal of the object. Read more
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fn notify(&self, property_name: &str)

Notify that the given property has changed its value. Read more
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fn notify_by_pspec(&self, pspec: &ParamSpec)

Notify that the given property has changed its value. Read more
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fn downgrade(&self) -> WeakRef<T>

Downgrade this object to a weak reference.
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where F: FnOnce() + Send + 'static,

Add a callback to be notified when the Object is disposed.
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fn bind_property<'a, 'f, 't, O>( &'a self, source_property: &'a str, target: &'a O, target_property: &'a str, ) -> BindingBuilder<'a, 'f, 't>
where O: ObjectType,

Bind property source_property on this object to the target_property on the target object. Read more
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Returns the strong reference count of this object.
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Runs the dispose mechanism of the object. Read more
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type Value = T

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type Value = T

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