🚀 go-pugleaf

I'm looking for some tools ont eh mac that will allow some serious text
processing, I particularly need to do the following:

1, I have an alaphetical text file (newsgroups) with lots of duplicate
entries which I want removed, someone suggested I use Excel but it
complained that the data had only one column.
2, I want to extract lines contianing a specific string to a text file
or allow me to give it a string with wildcards (full regex even) to
extract to a file.  I need to extract all the message-ids of the
postings I have made from a text file, so either I want to be able to
type "Message-id:" and it'll extract the whole lines to a file or type
something like "Message-id: <*>" to extract just that specific text with
anything replacing the *.

Any help much appreciated.
-- 
-> The email address in this message *IS* Valid <-