your split works in a scalar context, so you need:

(undef, $userid) = split "/", ....
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Which doesn't match both cases, so you need:

(undef, $userid) = split "/|\\\\", $ENV{REMOTE_USER};
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Yes, you need 4 slashes.

Also in your regex you need to escacpe the backslash:

$username =~ m#(cyc)/|\\(.*)#;
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--
Leviathan.