Thanks for replying so quickly. I'm not quite as advanced as you, and I understood most everything, except the following...

 my $outMode = '+>';

Is the +> telling the file to move out? What is the '+' for?

 open my ($outFh), $outMode, $outputFile;

Here, I know you open a filehandle and then there's the $outMode again (+>) and I'm assuming the name of the output file?

 $callBack->($outFh);

I'm just confused here.

 not $flag

I looked this up in perldocs. Does it return true if $flag = 0?

I didn't mean to turn this into a tutoring session, but it would help me out so much if I understood it! You've been a great help so far.Thanks.