PHP ban ips if in file

<?php
$lines = file('ips.txt');
$myproto = 'http';
$mywebsiteurl = 'example';
$endingstring = 'com';
// you can use the 3 variables above(myproto, websiteurl, endingstring) in the exit message if you want. you can do {$myproto}://{$mywebsiteurl}.{$endingstring}
// Loop through our array, show HTML source as HTML source; and line numbers too.
foreach ($lines as $line_num => $line) {
    $visitorIP = $_SERVER['REMOTE_ADDR'];
    //DEV TEST: $visitorIP = '90.90.90.90';
    if($line==$visitorIP&&!empty($visitorIP)) {exit('IP Address is blacklisted/banned');
    }
}
?>