php CURL

CURL是一个非常强大的开源库，支持很多协议，包括HTTP、FTP、TELNET等，我们使用它来发送HTTP请求。它给我 们带来的好处是可以通过灵活的选项设置不同的HTTP协议参数，并且支持HTTPS。CURL可以根据URL前缀是“HTTP” 还是“HTTPS”自动选择是否加密发送内容。

使用CURL发送请求的基本流程

使用CURL的PHP扩展完成一个HTTP请求的发送一般有以下几个步骤：

1. 初始化连接句柄；
2. 设置CURL选项；
3. 执行并获取结果；
4. 释放VURL连接句柄。

下面的程序片段是使用CURL发送HTTP的典型过程

// 1. 初始化
 $ch = curl_init();
 // 2. 设置选项，包括URL
 curl_setopt($ch,CURLOPT_URL,"http://www.devdo.net");
 curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
 curl_setopt($ch,CURLOPT_HEADER,0);
 // 3. 执行并获取HTML文档内容
 $output = curl_exec($ch);
 if($output === FALSE ){
 echo "CURL Error:".curl_error($ch);
 }
 // 4. 释放curl句柄
 curl_close($ch);

get方式：

 //初始化
    $curl = curl_init();
    //设置抓取的url
    curl_setopt($curl, CURLOPT_URL, 'http://www.baidu.com');
    //设置头文件的信息作为数据流输出
    curl_setopt($curl, CURLOPT_HEADER, 1);
    //设置获取的信息以文件流的形式返回，而不是直接输出。
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    //执行命令
    $data = curl_exec($curl);
    //关闭URL请求
    curl_close($curl);
    //显示获得的数据
    print_r($data);

post方式：

 //初始化
     $curl = curl_init();
     //设置抓取的url
     curl_setopt($curl, CURLOPT_URL, 'http://www.baidu.com');
     //设置头文件的信息作为数据流输出
     curl_setopt($curl, CURLOPT_HEADER, 1);
     //设置获取的信息以文件流的形式返回，而不是直接输出。
     curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
     //设置post方式提交
     curl_setopt($curl, CURLOPT_POST, 1);
     //设置post数据
     $post_data = array(
         "username" => "coder",
         "password" => "12345"
         );
     curl_setopt($curl, CURLOPT_POSTFIELDS, $post_data);
     //执行命令
     $data = curl_exec($curl);
     //关闭URL请求
     curl_close($curl);
     //显示获得的数据
     print_r($data);

下面是php手册中的一个curl类：

<?php 
class mycurl { 
     protected $_useragent = 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1'; 
     protected $_url; 
     protected $_followlocation; 
     protected $_timeout; 
     protected $_maxRedirects; 
     protected $_cookieFileLocation = './cookie.txt'; 
     protected $_post; 
     protected $_postFields; 
     protected $_referer ="http://www.google.com"; 

     protected $_session; 
     protected $_webpage; 
     protected $_includeHeader; 
     protected $_noBody; 
     protected $_status; 
     protected $_binaryTransfer; 
     public    $authentication = 0; 
     public    $auth_name      = ''; 
     public    $auth_pass      = ''; 

     public function useAuth($use){ 
       $this->authentication = 0; 
       if($use == true) $this->authentication = 1; 
     } 

     public function setName($name){ 
       $this->auth_name = $name; 
     } 
     public function setPass($pass){ 
       $this->auth_pass = $pass; 
     } 

     public function __construct($url,$followlocation = true,$timeOut = 30,$maxRedirecs = 4,$binaryTransfer = false,$includeHeader = false,$noBody = false) 
     { 
         $this->_url = $url; 
         $this->_followlocation = $followlocation; 
         $this->_timeout = $timeOut; 
         $this->_maxRedirects = $maxRedirecs; 
         $this->_noBody = $noBody; 
         $this->_includeHeader = $includeHeader; 
         $this->_binaryTransfer = $binaryTransfer; 

         $this->_cookieFileLocation = dirname(__FILE__).'/cookie.txt'; 

     } 

     public function setReferer($referer){ 
       $this->_referer = $referer; 
     } 

     public function setCookiFileLocation($path) 
     { 
         $this->_cookieFileLocation = $path; 
     } 

     public function setPost ($postFields) 
     { 
        $this->_post = true; 
        $this->_postFields = $postFields; 
     } 

     public function setUserAgent($userAgent) 
     { 
         $this->_useragent = $userAgent; 
     } 

     public function createCurl($url = 'nul') 
     { 
        if($url != 'nul'){ 
          $this->_url = $url; 
        } 

         $s = curl_init(); 

         curl_setopt($s,CURLOPT_URL,$this->_url); 
         curl_setopt($s,CURLOPT_HTTPHEADER,array('Expect:')); 
         curl_setopt($s,CURLOPT_TIMEOUT,$this->_timeout); 
         curl_setopt($s,CURLOPT_MAXREDIRS,$this->_maxRedirects); 
         curl_setopt($s,CURLOPT_RETURNTRANSFER,true); 
         curl_setopt($s,CURLOPT_FOLLOWLOCATION,$this->_followlocation); 
         curl_setopt($s,CURLOPT_COOKIEJAR,$this->_cookieFileLocation); 
         curl_setopt($s,CURLOPT_COOKIEFILE,$this->_cookieFileLocation); 

         if($this->authentication == 1){ 
           curl_setopt($s, CURLOPT_USERPWD, $this->auth_name.':'.$this->auth_pass); 
         } 
         if($this->_post) 
         { 
             curl_setopt($s,CURLOPT_POST,true); 
             curl_setopt($s,CURLOPT_POSTFIELDS,$this->_postFields); 

         } 

         if($this->_includeHeader) 
         { 
               curl_setopt($s,CURLOPT_HEADER,true); 
         } 

         if($this->_noBody) 
         { 
             curl_setopt($s,CURLOPT_NOBODY,true); 
         } 
         /* 
         if($this->_binary) 
         { 
             curl_setopt($s,CURLOPT_BINARYTRANSFER,true); 
         } 
         */ 
         curl_setopt($s,CURLOPT_USERAGENT,$this->_useragent); 
         curl_setopt($s,CURLOPT_REFERER,$this->_referer); 

         $this->_webpage = curl_exec($s); 
                   $this->_status = curl_getinfo($s,CURLINFO_HTTP_CODE); 
         curl_close($s); 

     } 

   public function getHttpStatus() 
   { 
       return $this->_status; 
   } 

   public function __tostring(){ 
      return $this->_webpage; 
   } 
} 
?> 

linux终端post请求-H添加请求头

curl -d "args"  "protocol://address:port/url"

linux终端get请求-H添加请求头

curl http://www.baidu.com