You could set it to a blank string if not defined like this 
#!/usr/bin/perl

use warnings;
use strict;

$ARGV[0] ||= '';

if ($ARGV[0] eq 'TEST') {
    print "$ARGV[0]\n";
}

[download]
or check for it being defined like this 
#!/usr/bin/perl

use warnings;
use strict;

if (defined($ARGV[0]) && $ARGV[0] eq 'TEST') {
    print "$ARGV[0]\n";
}

[download]
I prefer the second option.

In reply to Re: using $ARGV without arguments by tcf22
in thread using $ARGV without arguments by Anonymous Monk

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