What does this regex mean?: (?s

Question

What does this mean in regex?

(?s:.+?)

specifically

(?s

I've seen things like non capture groups (?:regex), lookaheads but this is the first time I see something like this, I got it from the MarkDownExtra parser definition lists part.

I was unable to find it on http://www.regular-expressions.info/ and Google because you can't physically google question marks, so I am asking here.

Also isn't .+? the same as .*?

`.+` matches between 1 and unlimited times, `.*` matches between 0 and unlimited times. — admdrew, Mar 28 '14 at 17:41
http://regex101.com/ is another pretty good site for testing/explaining regexes. You have answers already, but for the record it says ("match the remainder of the group with the following options: s modifier: single line. Dot matches newline characters"). — TessellatingHeckler, Mar 28 '14 at 17:42
@aliteralmind Thank you, I don't know how I missed that, I guess I just didn't imagine it being a modifier at all. — Timo Huovinen, Mar 28 '14 at 17:52
`.+` one or more greedy, `.+?` one or more lazy, didn't know this. — Timo Huovinen, Mar 28 '14 at 18:40
Consider [RegexBuddy](http://regexbuddy.com) if you're on Windows. It's a great application for analyzing regexes. For constructing regexes, they also have [RegexMagic](http://www.regexmagic.com/), which I've not used. — aliteralmind, Mar 28 '14 at 18:43

score 2 · Answer 1 · answered Mar 28 '14 at 17:39

2

Using this link You can get explanation of your regex.

NODE                     EXPLANATION
--------------------------------------------------------------------------------
  (?s)                     set flags for this block (with . matching
                           \n) (case-sensitive) (with ^ and $
                           matching normally) (matching whitespace
                           and # normally)

answered Mar 28 '14 at 17:39

Sabuj Hassan

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You can use [this link](http://rick.measham.id.au/paste/explain.pl). Its made based on Perl's `YAPE::Regex::Explain` module. – Sabuj Hassan Mar 28 '14 at 17:41
@SabujHassan thank you for the link, it makes things much clearer than the much prettier regex101 website – Timo Huovinen Mar 28 '14 at 18:17

score 2 · Accepted Answer · answered Mar 28 '14 at 17:40

2

It is an inline modifier:

(?s)

That was extended so that only the part within the group is affected. This means that the . within the group will be on 'dotall' mode (or match newlines too).

answered Mar 28 '14 at 17:40

Jerry

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What does this regex mean?: (?s

2 Answers2