Grep is a linux command that is often overlooked but can be very useful when searching for stuff from a single string to a complicated regular expression. This article scratches the surface on it's power and should leave you with enough information to discover new uses for it.

http://www.iceteks.com/articles.php/grep/1

These tests are done on RH8.0 which is considered somehwhat old so it could be possible that things got changed.

And the reason for the -l was to have 1 file per line, since the other is multiple files per line which achieves undesirable results in these examples. Though the results would of been the same if I would of put the words in a file line per line, but just wanted to show examples using real-time situations.

I think grep is only a linux thing, but there is a windows program that does the same but I forget what it's called.

Do you want an apple pie with that?