hex EXPR
    hex     Interprets EXPR as a hex string and returns the corresponding
            value. (To convert strings that might start with either 0, "0x",
            or "0b", see "oct".) If EXPR is omitted, uses $_.

                print hex '0xAf'; # prints '175'
                print hex 'aF';   # same

            Hex strings may only represent integers. Strings that would
            cause integer overflow trigger a warning. Leading whitespace is
            not stripped, unlike oct(). To present something as hex, look
            into "printf", "sprintf", and "unpack".