random limit | seed ?seedval?
Generate a pseudorandom integer number greater than
or equal to zero and less than limit. If seed is
specified, then the command resets the random num-
ber generator to a starting point derived from the
seedval. This allows one to reproduce pseudorandom
number sequences for testing purposes. If seedval
is omitted, then the seed is set to a value based
on current system state and the current time, pro-
viding a reasonably interesting and ever-changing
seed.
This command is provided by Extended Tcl.