man byte_diff () - compare two strings
NAME
byte_diff - compare two strings
SYNTAX
#include <byte.h>
int byte_diff(const char *one,unsigned long len,const char *two);
DESCRIPTION
byte_diff returns negative, 0, or positive, depending on whether the string one[0], one[1], ..., one[len-1] is lexicographically smaller than, equal to, or greater than the string one[0], one[1], ..., one[len-1].
When the strings are different, byte_diff does not read bytes past the first difference.