Stand back! I don't understand regular expressions
November 18, 2009 12:44 PM Subscribe
How do I use regular expressions to express "at least one of each of these, but not necessarily in this order"?
posted by specialagentwebb to technology (17 answers total)
I'm working on setting password verification for a website (ASP .NET, if it matters), but I can't wrap my head around the regex. I've never been that great at regular expressions, but this has me boggled. I roughly understand the "one or more" part, and how to define letters, numbers, and special characters, but how to combine them?
Here are the rules:
The password must contain at least one lower-case letter, at least one capital letter, at least one number (0-9), and at least one special character (!@#$%^&*).
No whitespace allowed.
It must be at least 8 letters
It must have a special character in the first 7 positions
The first and last characters can not be numbers.
It can't contain the user's username (probably easier to make this a separate validation).
The first one is the one where I get really stumped. So what's the prognosis, Hivemind? Is it possible to evaluate all of this in one regex, or should I just do one validation for each requirement?