recieve a list of URLs and return all image sources from it

function get_image_sources($urls) {
  // get the contents of the pages
  $pages = array_map('file_get_contents', $urls);
  
  // find all img tags
  $matches = preg_grep('/<img[^>]+>/i', $pages);
  
  // find the src attribute
  $matches = array_map(function($line) {
    preg_match('/src="([^"]+)"/', $line, $matches);
    return $matches[1];
  }, $matches);
  
  return $matches;
}