One things I consider viataly important when writing code, make it readable. Something that are just as valuable in perl as any other language, if not more so given the oportunity to abuse perl.
Avoid side effects, ensure that each line has a specific purpose. Try to ensure that each line performs a single operation. This will save you hours in debugging and maintenence. Likes such as:
Should be split into several lines. Why write the code to be so difficult to read?
All in all very clever code, VERY hard to read, consequently its worth is much reduced.