phpCURL抓取网页内容

参考代码1：
<?php
// 创建一个新cURL资源
$ch = curl_init();
// 设置URL和相应的选项
curl_setopt($ch, CURLOPT_URL, "http://www.baidu.com/");
curl_setopt($ch, CURLOPT_HEADER, false);
// 抓取URL并把它传递给浏览器
$data = curl_exec($ch);
echo $data;
//关闭cURL资源，并且释放系统资源
curl_close($ch);
?>

参考代码2：
<?php
$szUrl = "http://www.baidu.com/";
$UserAgent = 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; .NET CLR 3.5.21022; .NET CLR 1.0.3705; .NET CLR 1.1.4322)';
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $szUrl);
curl_setopt($curl, CURLOPT_HEADER, 0);  //0表示不输出Header，1表示输出
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($curl, CURLOPT_ENCODING, '');
curl_setopt($curl, CURLOPT_USERAGENT, $UserAgent);
curl_setopt($curl, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($curl); 
echo $data;
//echo curl_errno($curl); //返回0时表示程序执行成功 如何从curl_errno返回值获取错误信息
exit();
?>