warn "*$zip*"; next unless
[download]

should be (note ; => ,)

warn "*$zip*", next unless
[download]

Also, you're not printing the good value back out. I would do something like:

perl -pi.bak -e 'chomp;my($x,$y)=split/\t/;do{warn"*$y*\n";next}unless
+$y=~/^\d{5}$/&&$y>713&&$y<99930;print"$x\t$y\n"' *.dat
[download]

Note: This code is lighly tested! YMMV

Update: Heh - really lightly tested. My code works if you change -p to -n. Ignore me. :-)

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We are the carpenters and bricklayers of the Information Age.

Don't go borrowing trouble. For programmers, this means Worry only about what you need to implement.

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.