external call

hi i think i want to run a number through an external (perl binary) checksum like script - it works like: checksum.pl 12345678 and prints result reason is don't know how to compile php-gtk (i only want to hide the check anyway) and the check code is not entirely mathematical and uses perls fancy string stuff to do check so may be difficult to code in php-gtk (certainly with my coding skills) is it possible to do this from inside php-gtk and capture the result ? my 50th attempt (below) may give you an idea of what i mean, then again it may not:-) function checkit($widget) { $checksum = exec("./checksum.pl $token2"); any clues more than welcome thanks in advance ian