How can I check if a URL exists via PHP?

Question

How do I check if a URL exists (not 404) in PHP?

Answer 1

function urlIsOk($url)
{
    $headers = @get_headers($url);
    $httpStatus = intval(substr($headers[0], 9, 3));
    if ($httpStatus<400)
    {
        return true;
    }
    return false;
}