How to extract all links of any web page using PHP

links-extract.php

<?php

function getAllLinks($url){
  $urlData = file_get_contents($url);
  $dom = new DOMDocument();
  @$dom->loadHTML($urlData);
  $xpath = new DOMXPath($dom);
  $hrefs = $xpath->evaluate("/html/body//a");
  for($i = 0; $i < $hrefs->length; $i++){
    $href = $hrefs->item($i);
    $url = $href->getAttribute('href');
    $url = filter_var($url, FILTER_SANITIZE_URL);
    if(!filter_var($url, FILTER_VALIDATE_URL) === false){
      $urlList[] = $url;  
    }
  }
  return array_unique($urlList);
}

$url = 'https://www.mokoshalb.com';
var_dump(getAllLinks($url));

?>