libunique lets you send messages with commands to a running
instance using unique_app_send_message(). The commands can be either
predefined or custom. Some of the predefined libunique commands have
equivalents in GApplication. Instead of sending the UNIQUE_ACTIVATE
g_application_activate(), instead of sending the
UNIQUE_OPEN command, call
UNIQUE_NEW and UNIQUE_CLOSE and user-defined commands don't
have direct replacement at this time.
As a replacement for custom commands, GApplication implements the
GActionGroup interface and lets you add a group of actions with
g_application_set_action_group(). The actions can then be invoked,
either by using the D-Bus interface for GAction directly, or by
g_action_group_activate_action() from another instance of
the GApplication. The GApplication documentation contains an
example for using GApplication with actions.
For more complex needs, GApplication supports passing entire commandlines to the running instance.