Regex to match url end-of-line or "/" character

Question

I have a url and I'm trying to match it to a regular expression to pull out some groups. The problem I'm having is that the url can either end or continue with a "/" and more url text. I'd like to match urls like this:

• http://server/xyz/2008-10-08-4
• http://server/xyz/2008-10-08-4/
• http://server/xyz/2008-10-08-4/123/more

But not match something like this:

• http://server/xyz/2008-10-08-4-1

So, I thought my best bet was something like this:

/(.+)/(\d{4}-\d{2}-\d{2})-(\d+)[/$]

where the character class at the end contained either the "/" or the end-of-line. The character class doesn't seem to be happy with the "$" in there though. How can I best discriminate between these urls while still pulling back the correct groups?

Answer 1

/(.+)/(\d{4}-\d{2}-\d{2})-(\d+)(/.*)?$

Answer 2

To match either / or end of content, use (/|\z)

This only applies if you are not using multi-line matching (i.e. you're matching a single URL, not a newline-delimited list of URLs).

To put that with an updated version of what you had:

/(\S+?)/(\d{4}-\d{2}-\d{2})-(\d+)(/|\z)

Note that I've changed the start to be a non-greedy match for non-whitespace ( \S+? ) rather than matching anything and everything ( .* )

Answer 3

I can't really comment on the regex itself, but I wanted to let you know about a very useful tool, Expresso, which will help you construct and test your regexes before you try and code for them.

Answer 4

You've got a couple regexes now which will do what you want, so that's adequately covered. What hasn't been mentioned is why your attempt won't work: Inside a character class, $ (as well as ^, ., and /) has no special meaning, so [/$] matches either a literal / or a literal $ rather than terminating the regex (/) or matching end-of-line ($).