Actually this script is called from another, which passes a $testDir variable so while this script has it initialized as empty it does get one on the command line. But that's a good point to check on and put in some error capturing, since that directory is consistent I can probably add something to make sure its going to get that value anyway and even if called on the command line it will be set.
This works well cross platform, the script is run on AIX, HPUX, Linux, Solaris and Windows and its been pretty solid on those, it just means any change I make has to be checked across those platforms as well. Ah well, life goes on.