AiTown - aitown-plugin

aitown-plugin is a library to facilitate working with plug-ins in aitown. Each plug-in designed for this framework consists of two files: a binary file representing a shared (dynamic) library and a text file describing the plug-in. Both must have same base name (used as a short name for plug-in; other plug-ins will use this name to identify the plugin), with the shared library having a system dependent extension (".dll", ".so", ...) and the description file ending in ".inf". This is the first version (1.0.0) of this implementation

As the file name is used to identify the plug-in, it should only consist of lowercase letters, digits and characters "_" and "-".

C interface

The shared library must export two functions:

• func_error_t plugin__initialize (
      plugin_manager *manager_,
      plugin_data_t *plugin_
  );
  This function is called when the plug-in is loaded. The library must respond with FUNC_OK or it will be unloaded on return. During this call the plug-in registers the interfaces it exposes.
• void plugin__terminate (
      plugin_manager *manager_,
      plugin_data *plugin_
  );
  This function is called before the plug-in is unloaded. During this call the plug-in unregisters the interfaces it exposes.

Description file

The description file consists of [sections] and value=key entries (see the example at the end of the section). In the list below required, as opposed to optional, identifies an option that, if not found, will prevent the plug-in from being loaded, and multiple indicates an option that, when used multiple times, adds to previos content instead of overwriting it.

---

[general] section

name=text [required]

the name to be presented to the user.

description=text [optional]

a one line description.

version=x.y.z [required]

the version of the binary; this exact format must be used, with x, y and z being positive integers.

manager=x.y.z [required]

the minimum version of the manager and the version to which the plug-in conforms; programs exposing an older manager will ignore this plug-in. Currently, there exists only one valid version: "1.0.0".

dependencies=a:x.y.z,b,c [optional, multiple]

The plug-ins that should be loaded before this plug-in is loaded.

---

[aitown] section

server=yes|no [optional, default yes]

the plug-in targets the server.

client=yes|no [optional, default yes]

the plug-in targets the client.

Plug-in search path

When a plug-in is requested for loading and no path is given (not even a relative path), then that plug-in is searched in following directories:

1. $PROGPATH/plugins
2. $env(AITOWN_PLUGIN_DIR)
3. $HOME/.aitown/plugins
4. $env(UNIXROOT)/usr/lib/aitown/plugins
5. /usr/lib/aitown/plugins
6. $env(UNIXROOT)/lib/aitown/plugins
7. /lib/aitown/plugins