From the NannyMUD documentation

LAST CHANGE

2001-01-06

FUNCTION

NAME
        id - test for identity of an object


LOCATION
Most objects.

SYNTAX
int id(string str);

DESCRIPTION
	Perhaps the most called local function in the mudlib, the 'id'
	function is used most frequently when a player attempts to look
	at something.  A non-zero value means the object responds to the
	name passed to it.


RETURN VALUES
	If 'id' returns a non-zero value, it means the object is identified
	by the string passed to the function.


NOTE
	Many parts of the mudlib check id() in objects very frequently.
	Bugs and inefficiencies are thus multiplied many fold when they
	occur in id().  However, it is an easy function to use and rarely
	will anyone cause a bug with it.

	Many of the standard mudlib objects (simple_weapon.c, monster.c, etc)
	have standard local functions for setting up the identities of
	objects.  Most commonly these include: set_name() and add_alias().
	Generally you should use them if they are available, instead of
	writing your own 'id' function.


EXAMPLE
        In an imaginary weapon:

	int id(string str) {
	    return str == "sword" || str == "long sword";
        }

	or with the verb 'swing' in a silly object:

	int id(string str) { return str == "cat" || str == "feline"; }

	void init() { add_action("verb_swing", "swing"); }

	int verb_swing(string str) {
	   if( !id(str) ) {
              /* Player did not type 'swing cat'.  Return 0 lets the action
		 'fall' through in case other objects define the action
		 'swing' */
	      notify_fail("Swing what?\n"); 
              return 0;
           }
	   ...
        }


SEE ALSO
        long in lfun/basic/long


SEE ALSO
        add_action in efun/object_related/add_action


SEE ALSO
        set_name in lfun/basic/set_name
        set_name in obj/quest_obj
        set_name in std/basic/stationary


SEE ALSO
        add_alias in std/basic/stationary