Hi, First, I disagree with the assertion that there are only two common versions of awk on UNIX systems :) As for the answer - http://invisible-island.net/mawk/CHANGES It was fixed on 20090726. Using a zero index is wrong, though, as noted in that ChangeLog entry. http://www.opengroup.org/onlinepubs/9699919799/utilities/awk.html """ substr(s, m[, n ]) Return the at most n-character substring of s that begins at position m, numbering from 1. If n is omitted, or if n specifies more characters than are left in the string, the length of the substring shall be limited by the length of the string s. """ Yes, I just got this months newsletter :-) Peter