…and of the Perl modules in general. I had the following problem:

Given a list of 16 character alphanumeric IDs, find all the lines from a large-ish (\~6GB) logfile which contain at least one of the IDs.

The naive approach was to construct a big regular expression like \W(\QID1 ...

This is an interesting problem which can appear in certain cases (although not very often). A little searching around led me to many posts stating that there is no easy solution and the following easy solution:

^((?!my string).)*$

It works as follows: the matching string must contain zero or more ...