Well, for one thing, you don't need all those single quotes in the hash accesses, because hash accesses allow for unquoted barewords -- they get quoted automatically, after a fashion -- unless there are characters in it that look like an expression, e.g. + ! @ $ / ... Also, you might want to localize CONST (local *CONST;), because otherwise you're using a global filehandle from a subroutine, which is generally considered bad practice. The return is happening before the close, so the close never occurs. Where is @timing_paths declared (are you using strict?)? And why do you need [$i++] when there's push around?

Just my \$0.02...

Update: Why are you assigning [] to an array? [] is an array reference. That means your array will have one item, a reference to an array with no elements. I'm not sure this is what you want...