You can convey a lot about a function's purpose with its name, much like that of a variable. Here are 
some guidelines – not hard-and-fast rules – about how you should name subroutines.

====== Rules ======
  - If they're primarily about **performing an activity**, name them with a **verb**, for example, //summarize or download//. 
  - If they're primarily about **returning information**, name them after **what they return**, for example, //greeting or header//. 
  - If they're about **testing** whether a statment is **true or not**, give them a name that **makes sense in an if** statement; starting with //is_… or can_…// helps, or if that isn't appropriate, name them with an **adjective**: for example, //is_available, valid, or readable//. 
  - Finally, if you're **converting** between one thing and another, try and **convey both things**. Traditionally this is done with an //2 or _to_// in the middle: //text2html, metres_to_feet//. That way you can tell easily what's being expected and what's being produced.

Above excerpted from "Beginning Perl", by Simon Cozens, http://www.perl.org/books/beginning-perl/