I don't relate the words 'Perl' and 'work' to be in the same sentence. Perl was my hobby years ago, now I get paid for it.. I don't consider writing Perl 'work'. BUT, as far as the question goes.. I use it for about 99% of what I do. The other 1% is shell scripting, and maybe some sed/awk when needed.
in reply to I use Perl at work for
Actually, it was funny. Yesterday, I was debugging with a co-worker and during this I had to do some various substitutions, or reformat text output files, etc... and any time I had to do something like that (which could be done in vi) I would do a one-liner or write a small script (if needed). My co-worker said "Man, you simply use Perl for everything!"