In Perl, how to match strings from two data sources, one a big text file, and the other a smaller text file, and code a whole example on the whiteboard (some pseudo code ok), including reading in both files. The output would be a report summarizing a subset of the big file. The key thing was the string was coming from a variable. So it needed to handle something in this way.
# $searchme from the big file, $matchme from the small file
if($searchme =~ m/$matchme/)
{
# emit the valid output as specified
}