php grep pattern link form website

i need to grep a url form this website.

https://tech.zecast.com/ibctamil/

 <?php
$arrContextOptions=array(
    "ssl"=>array(
        "verify_peer"=>false,
        "verify_peer_name"=>false,
    ),
);  

$response = file_get_contents("https://tech.zecast.com/ibctamil/", false, stream_context_create($arrContextOptions));

$dom = new DOMDocument;
libxml_use_internal_errors(true);
$dom->loadHTML($response );
$divs = $dom->getElementsByTagName('script');
foreach ($divs as $div) {
    if($div->getAttribute('class') == 'container') {
        $toot=$div->getAttribute('file');
    }
}
echo $toot;

 ?>`enter code here`

And finaly i need this url https://cdn.ibctamil.com/ibctamil/smil:ibc_tamil_tv.smil/playlist.m3u8?zecaststarttime=1522618598&zecastendtime=1522641998&zecasthash=Vr92PpUQHqJw2lRTjv_xno8PkY-1G5LxFdyBqg4xX8M=