strcmp() - determines the lexical relationship between two strings.
int strcmp( string one, string two );
This implementatin of strcmp() is identical to the one found in C
libraries. If string one lexically precedes string two, then strcmp()
returns a number less than 0. If the two strings have the same value,
strcmp() returns 0. If string two lexically precedes string one, then
strcmp() returns a number greater than 0. This efunction is particu‐
larly useful in the compare functions needed by sort_array(3).