Your hash doesn't have any three letter keys, and your substr doesn't return three letters. Perhaps you meant:

my @key_hash = sort {
    substr($a,0,3) cmp substr($b,0,3)
} keys %key_hash;

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We're not surrounded, we're in a target-rich environment!

In reply to Re: Sorting a hash of hashes by jasonk
in thread Sorting a hash of hashes by Anonymous Monk

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