Regex to ignore string in URL

Question

Trying to write regex for reddits subreddits. My regex will replace the subreddit name with a link, but I would like for it to ignore a link within a url that's already being displayed. For example let's say I have the following 3 strings.

https://www.reddit.com/r/starwars/comments/12345

/r/starwars

r/starwars

I'm trying to write regex that will match the bottom 2 strings but ignore the top one. I'm attempting to use regex LookBehind but haven't been able to get it to work. My current regex is:

(?<=[^m])\/?r\/([a-zA-Z_])+

I would have thought the ^m would ignore any string starting with the 'm' from the '.com'

How about [this regex](https://regex101.com/r/ph2Fog/1)? – TheLostMind Dec 27 '16 at 07:12 — TheLostMind, Dec 27 '16 at 07:12

score 1 · Accepted Answer · answered Dec 27 '16 at 07:14

1

You shouldn't need look-behind or anything fancy for this. Instead, use the ^ and $ (the beginning- and end-of-string operators). Try a regex like:

var pattern = /^\/?r\/[A-Za-z_]+$/;
pattern.test('https://www.reddit.com/r/starwars/comments/12345'); // false
pattern.test('/r/starwars/comments/12345'); // false
pattern.test('/r/starwars'); // true
pattern.test('r/starwars'); // true

answered Dec 27 '16 at 07:14

disatisfieddinosaur

1,502
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Thank you. I worked off your example and ended up using the following '/\/?r\/\w+(?!\S)/' – bertmaclin Jan 01 '17 at 18:25

Regex to ignore string in URL

1 Answers1