What do you expect my ($parent, $createtime) = split(/;/, <FILE>); to do? It splits the line read by <FILE> on ; and puts the first part in $parent and the second part in $createtime.
If it doesn't do that I suggest that you check your input, perhaps the lines are empty or do not contain a ;?
CountZero
"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law