Thank you for your response, ww. The book in chapter 5 in fact covers how to write the regular expression to search data with grouping, and later  print it. I realize now how vague I was being in the question and have changed it to reflect that the regular expression will not be hardcoded, but be <STDIN>

Switching topics: you object to the author invoking chomp before introducing it. That's perhaps pedagologicly sound, but it also misses (missed?) a critical lesson about learning Perl!

To be specific he requests, in chapter 3 that you

3. Store your important phone numbers in a hash. Write a program to look up numbers by the person's name.

I assumed values from <STDIN> would just match, and up till that point chomp isn't mentioned nor is the fact that the <STDIN> function throws in a /n at the end of every entry. I was bashing my head against the wall when the hash wasn't matching the entry, even if (so far as I could tell) it matched verbatim. It was only after pouring over the nodes here for awhile that I discovered the chomp function and what it did.

That being said, I'm sort of glad it happened. It forced me to reach out and do some (?=) as you mentioned.