flush and ob flush are not working
<p>here is my code. The <code>ob_flush()</code> and <code>flush()</code> functions are not working. Why? </p>

<pre><code>&lt;?php
function get_headers_curl($url)
{
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL,            $url);
    curl_setopt($ch, CURLOPT_HEADER,         true);
    curl_setopt($ch, CURLOPT_NOBODY,         true);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_TIMEOUT,        4);
    $r = curl_exec($ch);
    $r = split("\n", $r);
    return $r;
} 

$urls = file('users.txt', FILE_IGNORE_NEW_LINES);
foreach ($urls as $url) {
    $headers = get_headers_curl(trim($url));
    if (false !== stripos(implode("\n", $headers), "Apache")) {
        echo "$url ====&gt; ok" ;
        ob_flush();
        flush();
    }
}
?&gt;
</code></pre>
