One OT but related note is the use of for to read from a filehandle.

I got bitten by that before.

for will create the list and iterate over it. This means that if <DATA> is a filehandle to a file containing 1Gb of data, for will attempt to create the 1Gb+ list, thus bringing your system to its knees.

The 'safer' way to do this would be to use a while instead of for because it doesn't create the list.