If you want to do more than just simple file munging, then a one-liner on the command prompt is probably not for you.

Populate a .pl file with the code, and add some extra code to the end, comments and strict and warnings, and even newlines for readability. Then run that script.

If you tell us what it is you want to do, there may be a trick for it, but in general, just make a "real" script. See below posts for deleting backup files at the end.