[] indicate a character class. For example, /[24680]/ would match an even number, but not an odd number. '+' is one or more matches. '*' is 0 or more. Read perlre for more info.
------
We are the carpenters and bricklayers of the Information Age.
Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.