php uses proxy to access website method

<?php
 
$requestUrl = &#39;php.cn&#39;;
 
$ch = curl_init();
 
$timeout = 5;
 
curl_setopt ($ch, CURLOPT_URL, $requestUrl);
 
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
 
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
 
curl_setopt($ch, CURLOPT_PROXYAUTH, CURLAUTH_BASIC); //代理认证模式
 
curl_setopt($ch, CURLOPT_PROXY, "112.23.451.72"); //代理服务器地址
 
curl_setopt($ch, CURLOPT_PROXYPORT, 80); //代理服务器端口
 
//curl_setopt($ch, CURLOPT_PROXYUSERPWD, ":"); //http代理认证帐号，名称:pwd的格式
 
curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_HTTP); //使用http代理模式
 
$file_contents = curl_exec($ch);
 
curl_close($ch);
 
echo $file_contents;
 
?>