php获取网页请求状态程序示例_php技巧

本文就此简述php获取网页请求状态程序示例如下：

方法一，使用 fsockopen
（不推荐使用curl_getinfo!）
代码如下:
function get_http_code($url="localhost", $port=80, $fsock_timeout=10){
set_time_limit(0);
ignore_user_abort(true);

// 记录开始时间
list($usec, $sec) = explode(" ", microtime(true));
$timer['start'] = (float)$usec + (float)$sec;

// 校验URL
if(!preg_match("/^https?:＼/＼//i", $url)){
$url = "http://".$url;
}
// 支持HTTPS
if(preg_match("/^https:＼/＼//i", $url)){
$port = 443;
}

// 解析URL
$urlinfo = parse_url($url);
if(empty($urlinfo['path'])){
$urlinfo['path'] = '/';
}
$host = $urlinfo['host'];
$uri = $urlinfo['path'] . (empty($urlinfo['query'])?'':$urlinfo['query']);

// 通过fsock打开连接
if(!$fp = fsockopen($host, $port, $errno, $error, $fsock_timeout)){
list($usec, $sec) = explode(" ", microtime(true));
$timer['end'] = (float)$usec + (float)$sec;
$usetime = (float)$timer['end'] - (float)$timer['start'];

return array('code'=>-1, 'usetime'=>$usetime);
}

// 提交请求
$status = socket_get_status($fp);
$out = "GET {$uri} HTTP/1.1＼r＼n";
$out .= "Host: {$host}＼r＼n";
$out .= "Connection: Close＼r＼n＼r＼n";
$write = fwrite($fp, $out);
if(!$write){
list($usec, $sec) = explode(" ", microtime(true));
$timer['end'] = (float)$usec + (float)$sec;
$usetime = (float)$timer['end'] - (float)$timer['start'];

return array('code'=>-2, 'usetime'=>$usetime);
}

$ret = fgets($fp, 1024);
preg_match("/http＼/＼d＼.＼d＼s(＼d+)/i", $ret, $m);
$code = $m[1];
fclose($fp);

list($usec, $sec) = explode(" ", microtime(true));
$timer['end'] = (float)$usec + (float)$sec;
$usetime = (float)$timer['end'] - (float)$timer['start'];

return array('code'=>$code, 'usetime'=>$usetime);
}

file_get_contents 是 fsockopen 功能的简单打包，效率稍低些，但是抓取成功率很高，所以在 snoopy 出问题的时候我一般拿他来用。5.0.0 添加了对 context 的支持，有了context，他也可以发送 header 信息，自定义用户 agent, referer, cookies 都不在话下。5.1.0 添加了 offset 和 maxlen 参数，可以只读文件的一部分内容。

方法二，使用snoopy.class.php

Snoopy是一个php类，用来模拟浏览器的功能，可以获取网页内容，发送表单。

代码如下:
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://www.gxlcms.com/');
curl_setopt($ch, CURLOPT_RANGE, '0-500');
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
$result = curl_exec($ch);
curl_close($ch);
echo $result;

$writefn = function($ch, $chunk) {
static $data='';
static $limit = 500; // 500 bytes, it's only a test
$len = strlen($data) + strlen($chunk);
if ($len >= $limit ) {
$data .= substr($chunk, 0, $limit-strlen($data));
echo strlen($data) , ' ', $data;
return -1;
}
$data .= $chunk;
return strlen($chunk);
};
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, 'http://www.gxlcms.com/');
curl_setopt($ch, CURLOPT_RANGE, '0-500');
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
curl_setopt($ch, CURLOPT_WRITEFUNCTION, $writefn);
$result = curl_exec($ch);
curl_close($ch);

一些常见的状态码为：
200 - 服务器成功返回网页
404 - 请求的网页不存在
503 - 服务器超时
301 - 页面重定向