2010-02-22, 08:12 #37 kar_bon     Mar 2006 Germany 13·229 Posts @Ian: thanks for the information and an amazing wide range of testing. thanks. @Max; i had a closer look to you WIN-perl script. if i understand perl correct, the function checkForPrimes will write found primes in the dedicated file when $individualPrimeLog = true. but you test to if($line != "") so if i'm right every time (workfile.res exists when cllr is done but if no prime is found, contains only the header line!) the header will be backuped, too! i've not tested it running yet, but will do today. nice quick work!