From the NannyMUD documentation

LAST CHANGE

2002-01-17

FUNCTION

NAME
        check_busy - See if a player is busy and/or make him busy.


LOCATION
        This function is located in /obj/player.

AVAILABILITY
        This function can be called by any object.

SYNTAX
        int check_busy(int heart_beats)

DESCRIPTION
        The function returns 1 if the player is currently busy; if not the
        player is made busy for the number of heartbeats as detailed by the
        function call and zero is returned.


EXAMPLE
        check_busy()    The same as check_busy(1).
        check_busy(12)  Make the player busy for 12 heartbeats if he isn't.


SEE ALSO
        query_busy in lfun/player/query_busy
        query_busy in std/transport/interior