http://www.perlmonks.org?node_id=909872

ZWcarp has asked for the wisdom of the Perl Monks concerning the following question:

Hello Perl Monks

I was wondering if anyone knew a good one liner for comparing the values in two separate lists and printing a "venn diagram" so to speak, of what appears in both, and in one or the other exclusively.

For example, lets say file1.txt has 300 patient IDs and file2.txt has 400 patient IDs, both arranged in one column. Some of the patient IDs are shared between the two lists, while others are exclusive to one or the other. Is there a good perl -ne one liner to sort of quickly check to see which IDs occur in both and which do not. I know how to do this in a script but the column positions of the data im interested as well as its format change, so it would be easier to just do through bash somehow.

Thanks so much for your help, it is very appreciated.