Extract all links of a webpage in php

Extracting all links of a webpage is quite easy with simple HTML Dom and Curl. Just read the webpage with Curl and parse it with Dom to extract all links. Here is the script.

    $url = "http://google.com";
    $agent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13";

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
    curl_setopt($ch, CURLOPT_MAXREDIRS, 2);
    curl_setopt($ch, CURLOPT_USERAGENT, $agent);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
    curl_setopt($ch, CURLOPT_TIMEOUT, 20);
    $html= curl_exec($ch);
    curl_close($ch);
    
    $dom = new DOMDocument();
    $dom->loadHTML($html);
 
    $hrefs = $dom->getElementsByTagName('a');
    $urls=array();
 
    for ($i = 0; $i < $hrefs->length; $i++) {
      $href = $hrefs->item($i);
      $urls[] = $href->getAttribute('href');
    }
    
    print_r($urls);
   

All Links will be stores in $urls array.