php验证网站404页面的两种方法

<?php
header('content-type:text/html;charset=utf-8');
function http_status_404($url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 1);
curl_setopt($ch, CURLOPT_NOBODY, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 5);
curl_exec($ch);
$status = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
return ($status == 404) ? '404页面' : '可正常访问';
}

echo http_status_404('http://blog.sijiaomao.com/?p=36996');

echo http_status_404('http://blog.sijiaomao.com/?p=1397');

// two

$headers = get_headers('http://blog.sijiaomao.com/?p=1397');

if (strpos($headers[0], '404'))
{echo "404";}else{
echo '正常访问';
}