I don't know anything about C++ or the framework of the chat commands sadly. Now I know what you want though... took a quick look through the command stuff. Try this though, no promises :P
Code:
bool ChatHandler::HandleUnInvisible(const char* args, WorldSession *m_session)
{
if(!*args) return false;
char msg[256];
Player *ptarget = objmgr.GetPlayer(args, false);
if(!ptarget) return false;
snprintf(msg, 256, "Attempting to remove invisibility and invincibility from player...");
if(ptarget->m_isGmInvisible)
{
ptarget->m_isGmInvisible = false;
ptarget->m_invisible = false;
ptarget->bInvincible = false;
ptarget->Social_TellFriendsOnline();
snprintf(msg, 256, "Now UnInvisible", msg);
} else {
snprintf(msg, 256, "That player is not GM Invisible.", msg);
}
snprintf(msg, 256, "UnInvisible Command was a success!", msg);
GreenSystemMessage(m_session, (const char*)msg);
return true;
}