Perl certainly had its detractors, but for a few years there it was the lingua franca of system administration.
It's still what I reach for first when I need to write a state machine that processes a file made up of lines with some--or some set of--structures. The integration of regexps is far, far, far superior to what Python can do, and I adore the while(<>) construct. Maintaining other people's Perl usually sucks, but it's a very easy way to solve your own little problems.
Adam