/**
* Signature of any function exported by a plugin.
+ *
+ * @param arg argument to the function (context)
+ * @return some pointer, NULL if the plugin was
+ * shutdown or if there was an error, otherwise
+ * the plugin's API on success
*/
typedef void *(*GNUNET_PLUGIN_Callback) (void *arg);
+/**
+ * Test if a plugin exists.
+ *
+ * Note that the library must export a symbol called
+ * "library_name_init" for the test to succeed.
+ *
+ * @param library_name name of the plugin to test if it is installed
+ * @return GNUNET_YES if the plugin exists, GNUNET_NO if not
+ */
+int GNUNET_PLUGIN_test (const char *library_name);
+
/**
* Setup plugin (runs the "init" callback and returns whatever "init"
* returned). If "init" returns NULL, the plugin is unloaded.
*
* @param library_name name of the plugin to load
* @param arg argument to the plugin initialization function
- * @return whatever the initialization function returned
+ * @return whatever the initialization function returned, NULL on error
*/
void *GNUNET_PLUGIN_load (const char *library_name, void *arg);
*
* @param library_name name of the plugin to unload
* @param arg argument to the plugin shutdown function
- * @return whatever the shutdown function returned
+ * @return whatever the shutdown function returned, typically NULL
+ * or a "char *" representing the error message
*/
void *GNUNET_PLUGIN_unload (const char *library_name, void *arg);