Many thanks for your help and above all for taking the pains to comment the code. Walking through it helped me understand what was wrong with my approach. The script worked and was fast and neatly segregated the two types.

---------- Post updated at 07:23 PM ---------- Previous update was at 07:18 PM ----------

Many thanks. I walked through the code and also your comments. I now understand why my script kept on giving very few results. Most importantly I learnt how to hash data in Perl. Aia's script was the add-on. Thanks to forum members for help and above all the pains people take to correct and comment on code written by people struggling with code.