But to at least illustrate what I'm talking about, consider:

  if (undef($a) || undef($b)) { ... }
[download]

and then there's the ever popular

  if ($a = 1) { ... }
[download]

I'd put these two in the category of "Common Goofs for Novices". The Camel Book has a section dedicated to this. So, in addition to your competition, I'd be interested in seeing a list of common Perl goofs. I've certainly seen plenty over the years, since we have a lot of "occasional" Perl programmers at work. Some random ones that I remember seeing often at work are:

• @x[42] instead of $x[42].
• print FH, "hello\n";
• /$name/ where $name might contain regex metachars (should use /\Q$name\E/ instead).
• /some regex/; $x = $1 .... That is, using $1 et al without checking that the regex actually matched.

Related to this is a WTF-style competition. I noticed an amusing one reported by Dominus the other day, namely what is wrong with this code?

for my $k (keys %hash) {
    if ($k eq "name") {
        $hash{$k}++;
    }
}
[download]

Answer: it is better written as $hash{name}++ ... which is an example of the classic Larry quote: Iterating over the keys of a hash is like clubbing someone to death with a loaded Uzi. :-)