Adjust this regex for urls

Question

Hi guys trying to sort my regex out for bbcodes.

I have this at the moment for urls:

 "/\[url\=\'(.+?)\'\](.+?)\[\/url\]/is",

That will only get urls already encased in '', how can i get it to check for urls with and without surrounding single quotes?

Which language would this regular expression be used in?

Linus Kleen
– Linus Kleen

2012-11-28 01:41:50 +00:00
Commented Nov 28, 2012 at 1:41 — Linus Kleen
– Linus Kleen, Commented Nov 28, 2012 at 1:41

minopret · Accepted Answer · 2012-11-28 01:42:43Z

You can use an alternation of patterns, the construct that uses the vertical bar (|).

"/\[url\=(\'(.+?)\'|([^'].+?))\](.+?)\[\/url\]/is",

Francis Gagnon · Accepted Answer · 2012-12-01 14:24:14Z

1

You could use this regex:

\[url=(?:'([^']+)'|"([^"]+)")\](.+?)\[\/url\]

It accepts single quote, double quote and no quote delimited url values. The downside is that you have to check multiple capture groups to get the URL attribute value.

Here are the capture groups:

Group 1: The value found if the attribute is single quote delimited.
Group 2: The value found if the attribute is double quote delimited.
Group 3: The text between the URL tags.

If you don't allow square brackets to appear between the URL tags, you could use the following regex instead. It will find a match more quickly in this case.

\[url=(?:'([^']+)'|"([^"]+)")\]([^\[]+)\[\/url\]

edited Dec 1, 2012 at 14:24

answered Nov 28, 2012 at 2:49

Francis Gagnon

3,6751 gold badge18 silver badges26 bronze badges

4 Comments

NaughtySquid Over a year ago

When you say "If you don't allow square brackets to appear between the URL tags, you could use the following regex instead. It is better because it uses a greedy repetition character." what do you mean by that?

NaughtySquid Over a year ago

Also the second regex is invalid?

Francis Gagnon Over a year ago

@LiamDawe - The greedy part ([^[]+) helps the regex match more quickly with less backtracking by consuming a whole chunk of characters until it can't anymore. A tool like RegexBuddy makes this very easy to see. Using (.+?) on the other hand consumes one character then tries to match the [, fails, backtracks, consumes another character with (.+?), tries to match the [, backtracks... until the match is found.

Francis Gagnon Over a year ago

@LiamDawe - I re-tested the second regex and it seems to work fine, although I didn't try it in PHP. I did omit the usual forward slashes though, did you use: /[url=(?:'([^']+)'|"([^"]+)"|([^\s'"]]+))]([^[]+)[\/url]/is

Collectives™ on Stack Overflow

Adjust this regex for urls

2 Answers 2

Comments

4 Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

4 Comments

Related