Regex for finding custom URLs

Question

I want to create a regex to match URLs that start with http://, https://, // or to find urls that have an extension different from html, htm, php and php3. URL query substrings are optional

Let's say that I want to find these:

http://example.com
/example.mp3
/example.mp3?q=example
http://example.com/example.mp3
#example

And to reject these:

example
/example
/example/
/example.htm
/example.htm?q=example
/example.mp3/example //The .mp3 needs to be extension to be accepted
/example#example

I already tried this /(^(http:\/\/|https:\/\/|\/\/|#)|(.*)((.*)\.^(?!html|htm|php|php3)$)(\?.*)?$)/igm but it didn't worked.

If the opposite(reversing the accepted and declined lists) is easier to do, even that is very appreciated, I can change the function that handles the regex.

It's not clear why you want to find #example but not /example#example — Oriol
– Oriol, Commented Dec 11, 2016 at 19:37
Your example and description of accepted parameters is slightly different. Do you want to accept / or //? — wizebin
– wizebin, Commented Dec 11, 2016 at 19:38
@Oriol #example can be an anchor to an id in the same page and /example#example can be an anchor to and id in another page — Ioan
– Ioan, Commented Dec 11, 2016 at 19:40
@wizebin i dont want to accept // (cross-origin) and to accept / (same-origin) — Ioan
– Ioan, Commented Dec 11, 2016 at 19:40

Wiktor Stribiżew · Accepted Answer · 2016-12-11 20:13:57Z

1

It seems you may use

^(?:#.+|(?:https?:/)?/[^?#\n]*\.(?!(?:html?|php3?)\b)\w+(?:\?.*)?)$

See the regex demo

Pattern details:

^ - start of string
(?:#.+ - either a # followed with any 1+ chars
| - or
(?:https?:/)?/[^?#\n]*\.(?!html?|php3?)\w+(?:\?.*)?) -
- (?:https?:/)?/ - an optional http:/ or https:/ and then /
- [^?#]* - 0+ chars other than ? and #
- \. - a dot
- (?!(?:html?|php3?)\b)\w+ - 1 or more letters/digits/underscore that is not equal to htm, html, php or php3
- (?:\?.*)?) - an optional ? followed with any 0+ chars
$ - end of string

answered Dec 11, 2016 at 20:13

Wiktor Stribiżew

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1 Comment

Ioan Over a year ago

Thank you for the answer! The code seemed a little bit harder at the first sight but the explications made me to understand the code way better.

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