$txt="http://rus-yurist.ru/images/plashka_1.png
      http://rus-yurist.ru/images/plashka_2.png
      http://rus-yurist.ru/images/plashka_3.png";

$a1=explode("n",$txt);
$a1=array_unique($a1);

foreach($a1 as $url) {
    $ch = curl_init($url);
    $path_parts = pathinfo($url);
    $path = 'docs/'.$path_parts['basename'];
    copy($url, $path);
 //  file_put_contents($path, file_get_contents($url)); /* not works too, only last file