Despite the power and truth of Jamie Zawinski's law:
Regular Expressions: Now You Have Two Problems Jeff Atwood's Perspective
Like Jeff, I too really, really love regular expressions or regexes. I use this one a lot and I finally learned to use \S (Any non-whitespace character) so here's a regex
that I wrote yesterday to "validate" the permitted characters in an Internet domain. I was all proud of this and wrote this blog post only to realize that pride really does goeth before a fall – this will NOT correctly validate an Internet domain. As I write this post, I realize that the number of allowed characters in an Internet domain are actually NOT any non-whitespace characters and here's the proof that I actually got that wrong yesterday when I put something online using it:
Note: The fact that Rubular allows through an _ which is NOT a valid character in domains is problematic.
So the right way to do this, DAMN IT, is something like this:
And this actually works:
The [A-Za-z0-9-]+ is a "character class" which says "Any uppercase or lowercase letter plus 0-9 plus a -" are allowed (any order, any quantity)".
Regular Expressions – Now you have two problems.
Posted In: #regex