file_get_contents 
<?php
$url = http://www.xxx.com/;
$contents = file_get_contents($url);
//如果出现中文乱码使用下面代码
//$getcontent = iconv("gb2312″, "utf-8″,file_get_contents($url));
//echo $getcontent;
echo $contents;
?>


curl
<?php
$url = "http://sjolzy.cn/";
$ch = curl_init();
$timeout = 5;
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
//在需要用户检测的网页里需要增加下面两行
//curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
//curl_setopt($ch, CURLOPT_USERPWD, US_NAME.":".US_PWD); 
$contents = curl_exec($ch);
curl_close($ch);
echo $contents;
?>




fopen->fread->fclose
<?php
$handle = fopen ("http://sjolzy.cn/", "rb");
$contents = "";
do {
$data = fread($handle, 8192);
if (strlen($data) == 0) {
break;
}
$contents .= $data; 
} while(true);
fclose ($handle);
echo $contents;
?>

Ps1.使用file_get_contents和fopen必须空间开启allow_url_fopen。方法：编辑php.ini，设置 allow_url_fopen = On，allow_url_fopen关闭时fopen和file_get_contents都不能打开远程文件。

Ps2.使用curl 必须空间开启curl。
建议打开URL时使用file_get_contents()方法，可优化打开速度