PHP file_get_contents with textarea doesn't work

i want to get and filtre emails from html code for each website in a textarea.

the problem is :when i put +3 urls in the list the code retu no email 0, but when i put -3 urls all be fine.

so my textarea is

<textarea type=text name="list" id="list" rows="32" cols="40"></textarea>

and my php code is

$textarea = str_replace("", "n", $_POST['list']);  
$textarea = str_replace("r", "n", $textarea);  

$textarea = explode("n", $textarea);
foreach ($textarea as $line) { //here i want to made a test for every url per line. when i test +3 urls it doesent work :(

if (preg_match('/^https?/', $line)) {  //i want to check if the urls is valid


$text=file_get_contents($line); 
$res = preg_match_all("/[a-z0-9]+[_a-z0-9.-]*[a-z0-9]+@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,4})/i",$text,$matches);
if ($res) {
foreach(array_unique($matches[0]) as $email) {
echo $email. "n";
}
}
}
} 

i have some urls verified that retu emails for test, and when this list contien +3 urls it dosen't work, so my loop is incorrect or somethink. help me please. or another idea to extract emails from a list