Trying to match src part of HTML <img> tag Regular Expression

Question

I've got a bunch of strings already separated from an HTML file, examples:

<img alt="" src="//i.imgur.com/tApg8ebb.jpg" title="Some manly skills for you guys&lt;p&gt;&lt;span class='points-q7Vdm'&gt;18,736&lt;/span&gt;&nbsp;&lt;span class='points-text-q7Vdm'&gt;points&lt;/span&gt;  : 316,091 views&lt;/p&gt;">

<img src="//i.imgur.com/SwmwL4Gb.jpg" width="48" height="48">

<img src="//s.imgur.com/images/blog_rss.png">

I am trying to make a regular expression that will grab the src="URL" part of the img tag so that I can replace it later based on a few other conditions. The many instances of quotation marks are giving me the biggest problem, I'm still relatively new with Regex, so a lot of the tricks are out of my knowledge,

Thanks in advance

Answer 1

Use DOM or another parser for this, don't try to parse HTML with regular expressions.

Example:

$html = <<<DATA
<img alt="" src="//i.imgur.com/tApg8ebb.jpg" title="Some manly skills for you guys&lt;p&gt;&lt;span class='points-q7Vdm'&gt;18,736&lt;/span&gt;&nbsp;&lt;span class='points-text-q7Vdm'&gt;points&lt;/span&gt;  : 316,091 views&lt;/p&gt;">
<img src="//i.imgur.com/SwmwL4Gb.jpg" width="48" height="48">
<img src="//s.imgur.com/images/blog_rss.png">
DATA;

$doc = new DOMDocument();
$doc->loadHTML($html); // load the html

$xpath = new DOMXPath($doc);
$imgs  = $xpath->query('//img');

foreach ($imgs as $img) {
   echo $img->getAttribute('src') . "\n";
}

Output

//i.imgur.com/tApg8ebb.jpg
//i.imgur.com/SwmwL4Gb.jpg
//s.imgur.com/images/blog_rss.png

If you would rather store the results in an array, you could do..

foreach ($imgs as $img) {
   $sources[] = $img->getAttribute('src');
}

print_r($sources);

Output

Array
(
    [0] => //i.imgur.com/tApg8ebb.jpg
    [1] => //i.imgur.com/SwmwL4Gb.jpg
    [2] => //s.imgur.com/images/blog_rss.png
 )