You ARE skipping and... but you aren't actually DOING anything when you skip it. You load the WHOLE file into $input_file and match words and then skip, but you aren't removing the word from the file. You'd need a substitute s/// to REMOVE text, something like s/(\w[\w'-]*)/$ignore{lc $1} ? '' : $1/g though you'd probably be better off generating a regular expression that matches any words you want, rather than matching all words and comparing against a hash. There are modules out there to do that, I see Regexp::List, though I think there was another one...

That's assuming you just want to remove certain words not the whole line.

Edit Regexp::Assemble is the one I was trying to think of