Actually your code is only about 60,000 times faster than the OP's code. The large file is opened and read once for each line (60,000 times that is) in the smaller file in the OP's version. The smaller file is opened and read once only.

In other respects your reply is pretty much the same as ikegami and my replies ;).

Perl reduces RSI - it saves typing

In reply to Re^2: Compare 2 files and create a new one if it matches by GrandFather
in thread Compare 2 files and create a new one if it matches by shawshankred

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