With the onslaught of golf meditations recently (of which I shall soon be posting one -- fear not!), I'm posting a set of reminders that you may be wont to take heed of, ere you post again!
if you use a regex, be sure . can match a newline, by using the /s modifier to the regex
pop is two characters less than shift
assign to @_ and $_ if you can -- it saves a my declaration (if you're stingy), and allows operations like regexes and pop to work without an argument
screw $1 and the like, and use $& and its friends instead
map() is probably a useful tool to master for golf
leave out semicolons wherever possible
don't explicitly return unless you must
doing .$/ is shorter than ."\n" -- same for .$" vs. ." "