Regex Everything Including Whitespace - php

Question

I need a regular expression pattern all characters including whitespace what is not a variable in PHP.
<li class="xyz" data-name="abc">
<span id="XXX">some words</span>
<div data-attribute="values">
<a class="klm" href="http://example.com/blabla">somethings</a>
</div>
<div class="xyz sub" data-name="abc-sub"><img src="/images/any_image.jpg" class="qqwwee"></div>
</li><!--repeating li tags-->
I wrote a pattern;
preg_match_all('#<li((?s).*?)<div((?s).*?)href="((?s).*?)"((?s).*?)</li>#', $subject, $matches);
This works well but I don't want to get four variables. I just want to get
http://example.com/blabla
And anyone can tell me why this does not work like that?
preg_match_all('#<li[[?s].*?]<div[[?s].*?]href="((?s).*?)"[[?s].*?]</li>#', $subject, $matches);

Answer 1

Using (?:) will allow grouping but make those groups not captured, for example, the following:
#<li(?:(?s).*?)<div(?:(?s).*?)href="((?s).*?)"(?:(?s).*?)</li>#
Will output:
array (
0 =>
array (
0 => '<li class="xyz" data-name="abc">
<span id="XXX">some words</span>
<div data-attribute="values">
<a class="klm" href="http://example.com/blabla">somethings</a>
</div>
<div class="xyz sub" data-name="abc-sub"><img src="/images/any_image.jpg" class="qqwwee"></div>
</li>',
),
1 =>
array (
0 => 'http://example.com/blabla',
),
)
All of your matches will be contained in $matches[1], so iterate through that.

Answer 2

Don't use RegExps to parse HTML
Read this famous answer on StackOverflow.
HTML is not a regular language, so it cannot be reliably processed with a RegExp. Instead, use a proper (and robust) HTML parser.
Also note that data mining (analysis) != web-scraping (data collection).
If you don't want a regexp group to store the "captured" data, use a non-capturing flag.
(?:some-complex-regexp-here)
In your case, the following may work:
(?s)<li.*?<div.*?href="([^"]*?)".*?</li>
But seriously, don't use regexps for this; regexps are fragile. Use an xpath like /li//div//a//#href instead.