You are pushing $param onto your array but you are testing $_ in your regular expressions. As there isn't anyway to tell from the code you've posted what is actually in $param, it's hard to give advice. I can tell you that putting your anchors outside your parens will give you the behavior you want from your regex. (i.e. /^(a|b|c)$/ will match only the exact strings: 'a' or 'b' or 'c' update: or any of those strings with a newline appended.)

-sauoq
"My two cents aren't worth a dime.";