General UNIX puzzle

[Brett Glass]

At 02:44 PM 1/17/2004, Eric Anderson wrote:

>You should do your own Comp Sci homework. This looks like (especially considering the time of th year) the begining of a Unix Basics course.

Nope; I'm quite experienced with UNIX. However, I posted the
question because I wanted to see what the most efficient
and clever answers would be. For example, while I received
answers involving languages, such as sed and awk, the simplest 
answer to at least one of them seems to use grep.

--Brett