The osrs_oacti script is used by the Open Source Rule Set to handle the OnActivateItem event. The content of the script is the following.
///////////////////////////////////////////////////////////////////////////// // // file: // osrs_oacti // // purpose: // OnActivateItem event script. // ///////////////////////////////////////////////////////////////////////////// // the include file for Open Source Rule Set events #include "osrs_inc" ///////////////////////////////////////////////////////////////////////////// void main() { // determine what type of object is calling this script int iCallingClass = osrs_GetCallerEventClass(OBJECT_SELF); switch(iCallingClass) { ///////////////////////////////// module case I_OSRS_EVENT_CLASS_MODULE: // Module::OnActivateItem Pre-event if (!osrs_mo_oacti_pre()) { return; } // Module::OnActivateItem event if (!osrs_mo_oacti()) { return; } // Module::OnActivateItem post-event osrs_mo_oacti_post(); break; } }