Given a URL - extract all the link of the images?

[extrovertive]

Given a link/page, what's the best way to extract all the image urls of it? I know I can use $string = file_get_contents("http://www.domain.com"); and then  use regular expression to get all the link of the images.

 

But what if some images are like http://www.domain.com/resources/data.php?=123 It would be quite a difficult challenge to find the ones without the typical .jpg, .gif, or .png extensions.

 

Can anyone show me a simple script to do this?

[thebadbad]

The URLs would be found inside img tags (as the src attribute), right?

[extrovertive]

The URLs would be found inside img tags (as the src attribute), right?

 

Ah thanks. What would be the best method to do this? Use Curl? Use file_get_conents and extract the <img code? But how do I just grab the image URLs only?

[Alex]

<?php
$file = file_get_contents('http://www.phpfreaks.com/forums/index.php/topic,270900.0.html');
preg_match_all('~<img(.+?)src="(.+?)"~', $file, $matches);
print_r($matches[2]);
?>

 

That works, but to be honest it's probably not the best way, my regex is rusty.

[thebadbad]

You could use DOM to grab the URLs (better readability compared to regular expressions - but probably slower and takes up more lines). And I normally use cURL to get the remote contents:

 

<?php
function curl_load($url, $postdata = false) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
if (is_array($postdata)) {
	curl_setopt($ch, CURLOPT_POST, true);
	curl_setopt($ch, CURLOPT_POSTFIELDS, $postdata);
}
curl_setopt($ch, CURLOPT_FORBID_REUSE, true);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (Windows; U; Windows NT 6.0; da; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3');
$contents = curl_exec($ch);
curl_close($ch);
return $contents;
}
$site = 'http://example.com/';
$html = curl_load($site);
$dom = new DOMDocument();
$dom->loadHTML($html);
$tags = $dom->getElementsByTagName('img');
$urls = array();
foreach ($tags as $tag) {
if ($tag->hasAttribute('src')) {
	$urls[] = $tag->getAttribute('src');
}
}
echo '<pre>' . print_r($urls, true) . '</pre>';
?>

 

The grabbed URLs could be relative; here's how to convert them to absolute (append to the above code):

 

<?php
// http://w-shadow.com/blog/2007/07/16/how-to-extract-all-urls-from-a-page-using-php/
function relative2absolute($absolute, $relative) {
        $p = @parse_url($relative);
        if(!$p) {
        //$relative is a seriously malformed URL
        return false;
        }
        if(isset($p["scheme"])) return $relative;

        $parts=(parse_url($absolute));

        if(substr($relative,0,1)=='/') {
            $cparts = (explode("/", $relative));
            array_shift($cparts);
        } else {
            if(isset($parts['path'])){
                 $aparts=explode('/',$parts['path']);
                 array_pop($aparts);
                 $aparts=array_filter($aparts);
            } else {
                 $aparts=array();
            }
           $rparts = (explode("/", $relative));
           $cparts = array_merge($aparts, $rparts);
           foreach($cparts as $i => $part) {
                if($part == '.') {
                    unset($cparts[$i]);
                } else if($part == '..') {
                    unset($cparts[$i]);
                    unset($cparts[$i-1]);
                }
            }
        }
        $path = implode("/", $cparts);

        $url = '';
        if($parts['scheme']) {
            $url = "$parts[scheme]://";
        }
        if(isset($parts['user'])) {
            $url .= $parts['user'];
            if(isset($parts['pass'])) {
                $url .= ":".$parts['pass'];
            }
            $url .= "@";
        }
        if(isset($parts['host'])) {
            $url .= $parts['host']."/";
        }
        $url .= $path;

        return $url;
}

//for the absolute URL use the base href if found
$base = $dom->getElementsByTagName('base');
if ($base = $base->item(0)) {
if ($base->hasAttribute('href')) {
	$site = $base->getAttribute('href');
}
}
//convert URLs
$abs_urls = array();
foreach ($urls as $url) {
$abs_urls[] = relative2absolute($site, $url);
}
echo '<pre>' . print_r($abs_urls, true) . '</pre>';
?>

 

And my regex alternative:

 

<?php
preg_match_all('~<img\b[^>]+\bsrc\s?=\s?([\'"])(.*?)\1~is', $html, $matches);
$urls = $matches[2];
?>

 

and for grabbing the possible base tag:

 

<?php
if (preg_match('~<base\b[^>]+\bhref\s?=\s?([\'"])(.*?)\1~is', $html, $matches)) {
$site = $matches[2];
}
?>