If in the context of an app, put the lists into a pair of tables and write a simple SQL query to eliminate the dups. The resulting set will be what you're after. MySQL,sqllite,or any relational DB will work for this. <div class="gmail_quote">On Jul 28, 2012 3:47 AM, "Patton" <<a href="mailto:p.echols@comcast.net">p.echols@comcast.net</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On 07/27/2012 08:11 PM, William Scott Lockwood III wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> On Jul 27, 2012 10:09 PM, "Patton" <<a href="mailto:p.echols@comcast.net" target="_blank">p.echols@comcast.net</a> <mailto:<a href="mailto:p.echols@comcast.net" target="_blank">p.echols@comcast.net</a>>> wrote: > > I have a need to compare two lists of email addresses. Each one is a text file with address per line. What I need to output is a list of email addresses that are only in list B, I do not want the addresses that are in both or are only in A. > > I've read man diff, and it looks like I should be able to do it, but I cannot figure out how to do it and clearly do not understand some of how it should work. > > I am not married to using diff, anything that will get the result will be great. Any thoughts?? > > > -- > Patton I would run both files through sort, which will ensure the order is the same in both files, and then diff -u them both. </blockquote> the -u parameter seems to say it will output lines of "unified context." Not sure I know how that will help. -- Patton -- ubuntu-users mailing list <a href="mailto:ubuntu-users@lists.ubuntu.com" target="_blank">ubuntu-users@lists.ubuntu.com</a> Modify settings or unsubscribe at: <a href="https://lists.ubuntu.com/mailman/listinfo/ubuntu-users" target="_blank">https://lists.ubuntu.com/mailman/listinfo/ubuntu-users</a> </blockquote></div>