while (<SOURCE>) {
   $script = <SOURCE>;
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This ignores every second line in 30.txt, because it reads one item from SOURCE and assigns it to $_, and then another one and assigns it to $script. If that's not what you want, write while (my $script = <SOURCE>) { ... } or so instead.

It might also help if you gave us a little example of a few inputs, and what output you expect from them.