Regex for PHP: match a character within a set of quotes

Question

<input name="so and so" id="john doe" value="something something" />

I want to match only the space character that is within the " of a value= attribute.

I came up with this:

value="[^"',:<>/\r\n]*[ ][^"',:<>/\r\n]*"

Problem is this matches the whole string, where I just need the space in the matched string from above.

I am reading some tutorials, which leads me to think I need to use a conditional statement, but I can't seem to figure out how that would work. My guess (which of course didn't work) was:

(?(?=value="[^"',:<>/\r\n]*[^"',:<>/\r\n]*")[ ])

Any help is appreciated. Thanks!

Oh sorry it is for php – David Avellan Nov 08 '15 at 14:09 — David Avellan, Nov 08 '15 at 14:09

vks · Accepted Answer · 2015-11-08T15:09:09.167

1

\bvalue="\K|\G(?!^)[^"]*?\K\s+

You can use this to find spaces which are in value=" and before closing ".See demo.

https://regex101.com/r/lR1eC9/11

EDIT:

(?:(?<=\bvalue=")|\G(?!^))[^"]*?\K\s+(?=[^"=]*")

See demo.

https://regex101.com/r/lR1eC9/13

edited Nov 08 '15 at 15:09

answered Nov 08 '15 at 14:11

vks

67,027
10
91
124

That is close, but not quite working. It will match any string that starts with value=" . In your example, it matched value="dogcat without a closing a " or a space – David Avellan Nov 08 '15 at 14:15
Nevermind. It seems to work in the real world. :) Why does it report 4 matches though when there are only 3, and a new match each time you add a new value=" even if there is no closing " or /s? – David Avellan Nov 08 '15 at 14:23
2

@DavidAvellan Also try [like this modification](https://regex101.com/r/cF0xG7/1) of vks neat regex. – bobble bubble Nov 08 '15 at 14:24
I stand corrected, it is still producing too many matches. @bobblebubble has the best one that worked for me. – David Avellan Nov 08 '15 at 14:29
In your own link it is failing. It shows 4 matches when it should be showing 3. It matches whenever it sees: value=" – David Avellan Nov 08 '15 at 14:32
Look at the top right. It shows green box above your regex. It is actually 5 matches. Where as @bobblebubble produces 3 matches. – David Avellan Nov 08 '15 at 14:41
http://i.imgur.com/1QOYPFC.jpg – David Avellan Nov 08 '15 at 14:42
2

@DavidAvellan use this https://regex101.com/r/lR1eC9/13 – vks Nov 08 '15 at 14:48
That one works better and I would put that one in the answer. – David Avellan Nov 08 '15 at 15:06

Regex for PHP: match a character within a set of quotes

1 Answers1