There is a special event that can be put in a nam tracefile which allows us
to run different tcl procedures. This event is represented by event type v.
v -t time -e nam tcl procedure call
This event is very generic, in that it may execute several different procedures at a given time, as long as it is in one line (no more than 256 characters). There may be white spaces in the string which are passed as arguments to the tcl procedure. Unlike other events, the order of flags and the tcl procedure call is important.
Here are some examples of this event in use: