The fact that $ARGV[1] (thus ARCHIVE) is undef and not an empty string isn't really relevent. He's doing a test for string equality via eq, and undef stringifies to an empty string, so the test should succeed. 
$ perl -e 'print "OK\n" if undef eq ""'
OK

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In reply to Re: Re: Invalid use of constant pragma? by Fastolfe
in thread Invalid use of constant pragma? by dhable

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