regular expression to parse image url from a html code - regex

Question

Hello guys i wrote a module that creates some articles and css them properly and i want to parse the images from the Article content. The first thought came to my mind was the regular expressions. i didnt have any idea till 3 hours i started reading tutorials about regexp and i made a pattern that for me it seems kinda ok.
$pattern='^src\="images\/([a-zA-Z]+|[0-9]+)+([a-zA-Z]*|[0-9]*)*\.[jpg|png|bmp|gif]"$';
$regstring=$introtext;
preg_match($pattern,$regstring,$matches);
var_dump($matches);
INPUT:
<p>ASDADSDSASADSADSASDADSDSASADSADSASDADSDSASA</p>
<p><img src="images/authentic.jpg" alt="authentic" /></p>
<p>SASDADSDSASADSADSASDADSDSASADSADS</p>
I kinda found alot of ready patters in stackoverflow that are completly different than mine, and i didnt want to just copy some lines that i dont know what they do.Also i found out ten mins before that i can do that With DOM html , but im stubborn to make it work with regexpr so i can learn something more about it.
Can someone help me find what is my mistake/s ?
Thanks for your time.

Answer 1

src="images\/[a-zA-Z0-9]+\.(?:jpg|png|bmp|gif)"
You can try this.A simple version of your regex.See demo.
http://regex101.com/r/oE6jJ1/36

Answer 2

$pattern='/(?<=[\'\"])[\w\/-]+[.]{1}[a-zA-Z]{3,4}(?=[\'\"])/i';
$regstring=$introtext;
preg_match_all($pattern,$regstring,$matches);
var_dump($matches[0]);
you can see how this works here: http://regex101.com/r/eV6gE4/1

Answer 3

Use a proper solution, and please, stop killing kitties (every-time you try to parse HTML with regex, you kill a kittie) when you install perl module WWW::Mechanize, the command mech-dump become available :
$ mech-dump --images http://stackoverflow.com/questions/27151348
http://i.stack.imgur.com/qF63b.jpg?s=32&g=1
//cdn.sstatic.net/stackoverflow/img/apple-touch-icon.png
http://i.stack.imgur.com/nyAHT.jpg?s=32&g=1
/posts/27151348/ivc/677a
http://pixel.quantserve.com/pixel/p-c1rF4kxgLUzNc.gif