PHP 中和 HTTP 相关的函数及使用

① get_headers 方法：取得服务器响应一个 HTTP 请求所发送的所有标头

例如：

<?php
$httpinfo = get_headers('http://www.baidu.com', 1);
print_r($httpinfo);

使用 FF 的查看页面源码查看返回的结果（如果省略第二个参数，返回的则是索引数组）：

Array
(
    [0] => HTTP/1.1 200 OK
    [Date] => Sat, 24 Oct 2015 05:20:47 GMT
    [Content-Type] => text/html
    [Content-Length] => 14613
    [Last-Modified] => Tue, 02 Sep 2014 08:55:13 GMT
    [Connection] => Close
    [Vary] => Accept-Encoding
    [Set-Cookie] => Array
        (
            [0] => BAIDUID=57422D9DF880F51C9236D0AAC5AB11BA:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [1] => BIDUPSID=57422D9DF880F51C9236D0AAC5AB11BA; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [2] => PSTM=1445664047; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [3] => BDSVRTM=0; path=/
        )

    [P3P] => CP=" OTI DSP COR IVA OUR IND COM "
    [Server] => BWS/1.1
    [X-UA-Compatible] => IE=Edge,chrome=1
    [Pragma] => no-cache
    [Cache-control] => no-cache
    [BDPAGETYPE] => 1
    [BDQID] => 0xe5d2f28c001a4c17
    [BDUSERID] => 0
    [Accept-Ranges] => bytes
)

而使用 FF 直接访问百度（未登录），返回的 HTTP 响应头信息：

HTTP/1.1 200 OK
Server: bfe/1.0.8.5
Date: Sat, 24 Oct 2015 05:20:20 GMT
Content-Type: text/html; charset=utf-8
Transfer-Encoding: chunked
Connection: keep-alive
Vary: Accept-Encoding
Cache-Control: private
Cxy_all: baidu+acb608f22c032a75f48a12dcc3a4e51c
Expires: Sat, 24 Oct 2015 05:19:22 GMT
X-Powered-By: HPHP
X-UA-Compatible: IE=Edge,chrome=1
BDPAGETYPE: 1
BDQID: 0x9b2b20af00151024
BDUSERID: 0
Set-Cookie: BDSVRTM=0; path=/
BD_HOME=0; path=/
H_PS_PSSID=17522_1456_17619_17640_17001_17471_17073_15917_12248_17051; path=/; domain=.baidu.com
__bsi=11400537099011293757_00_0_I_R_4_0303_C02F_N_I_I_0; expires=Sat, 24-Oct-15 05:20:25 GMT; domain=www.baidu.com; path=/
Content-Encoding: gzip

一般使用 get_headers 方法请求一个 URL，根据其返回的数据判断状态码是否为 200 来判断所请求的资源是否存在。如果失败则返回 False 并发出一条 E_WARNING 级别的错误信息。

② file_get_contents 方法 和 $http_response_header 变量

使用 file_get_contents 打开一个 URL 时，会创建一个 $http_response_header 变量保存 HTTP 响应头信息（和 get_geaders 方法类似，get_headers 方法可以用过第二个参数是指定返回的保存 HTTP 响应头信息的数组是索引数组还是关联数组。而 $http_response_header 保存的是索引数组）：

<?php
$html = file_get_contents('http://www.baidu.com/');
print_r($http_response_header);

返回：

Array
(
    [0] => HTTP/1.1 200 OK
    [1] => Date: Sat, 24 Oct 2015 05:30:13 GMT
    [2] => Content-Type: text/html
    [3] => Content-Length: 14613
    [4] => Last-Modified: Tue, 02 Sep 2014 08:55:13 GMT
    [5] => Connection: Close
    [6] => Vary: Accept-Encoding
    [7] => Set-Cookie: BAIDUID=BCA76FCEBB02BA1E33EE2936557F4B93:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
    [8] => Set-Cookie: BIDUPSID=BCA76FCEBB02BA1E33EE2936557F4B93; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
    [9] => Set-Cookie: PSTM=1445664613; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
    [10] => Set-Cookie: BDSVRTM=0; path=/
    [11] => P3P: CP=" OTI DSP COR IVA OUR IND COM "
    [12] => Server: BWS/1.1
    [13] => X-UA-Compatible: IE=Edge,chrome=1
    [14] => Pragma: no-cache
    [15] => Cache-control: no-cache
    [16] => BDPAGETYPE: 1
    [17] => BDQID: 0xbd11b30400147402
    [18] => BDUSERID: 0
    [19] => Accept-Ranges: bytes
)

③ fopen 方法 和 stream_get_meta_data 方法:从封装协议文件指针中取得报头／元数据

<?php
$fp = fopen('http://www.baidu.com/', 'r');
print_r(stream_get_meta_data($fp));
fclose($fp);

返回

Array
(
    [wrapper_data] => Array
        (
            [0] => HTTP/1.1 200 OK
            [1] => Date: Sat, 24 Oct 2015 05:45:19 GMT
            [2] => Content-Type: text/html
            [3] => Content-Length: 14613
            [4] => Last-Modified: Tue, 02 Sep 2014 08:55:13 GMT
            [5] => Connection: Close
            [6] => Vary: Accept-Encoding
            [7] => Set-Cookie: BAIDUID=3D2EF009AB73DEF6A808146A1CB6BEF5:FG=1; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [8] => Set-Cookie: BIDUPSID=3D2EF009AB73DEF6A808146A1CB6BEF5; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [9] => Set-Cookie: PSTM=1445665519; expires=Thu, 31-Dec-37 23:55:55 GMT; max-age=2147483647; path=/; domain=.baidu.com
            [10] => Set-Cookie: BDSVRTM=0; path=/
            [11] => P3P: CP=" OTI DSP COR IVA OUR IND COM "
            [12] => Server: BWS/1.1
            [13] => X-UA-Compatible: IE=Edge,chrome=1
            [14] => Pragma: no-cache
            [15] => Cache-control: no-cache
            [16] => BDPAGETYPE: 1
            [17] => BDQID: 0xb0560df000168912
            [18] => BDUSERID: 0
            [19] => Accept-Ranges: bytes
        )

    [wrapper_type] => http
    [stream_type] => tcp_socket
    [mode] => r
    [unread_bytes] => 0
    [seekable] =>
    [uri] => http://www.baidu.com/
    [timed_out] =>
    [blocked] => 1
    [eof] =>
)

④ stream_context_creat 方法 和 file_get_contents 方法发送 POST 请求，模拟简单的灌输机器人

在构建 HTTP 请求头信息之前，可以先真实提交，查看真实提交的 HTTP 请求头信息：

post 的信息有：

如果返回以下内容则说明发送成功：

代码：

 <?php
 header("Content-type: text/html; charset=gb2312");
 set_time_limit(0);

 $data = array(
     'dopost' => 'send',
     'comtype' => 'comments',
     'aid' => 1083,
     'fid' => 0,
     'msg' => '轻轻的我来了',
     'username' => 'car',
     'notuser' => '',
     'face' => 6,
     'feedbacktype' => 'feedback',
     'pwd' => '',
     'validate' => '',
 );

 $data = http_build_query($data);
 //echo $data;
 //dopost=send&comtype=comments&aid=1083&fid=0&msg=%C7%E1%C7%E1%B5%C4%CE%D2%C0%B4%C1%CB&username=car&face=6&feedbacktype=feedback&pwd=&validate=&notuser=

 $opts = array(
     'http' => array(
         'method' => 'POST',
         'header' => "Content-type:application/x-www-form-urlencoded\r\n".
                     "Content-length:".strlen($data)."\r\n".
                     "Cookie:PHPSESSID=ee6jp9rhlom89p0apja3f7p983; LiveWSPAT63435038=1445669412671927548778; LiveWSPAT63435038sessionid
             =1445669412671927548778; NPAT63435038lastinvite=1445669563512; CNZZDATA1000207770=502543333-1445663698-
             %7C1445663698; CNZZDATA1256212238=1641575784-1445664133-%7C1445664133; browse=aid%3A1083%2C%u9F99%u51E4
             %u53E4%u7B5D-%u6960%u6728%u7D20%u9762%2Chttp%3A//www.bj-tygy.com/plus/view.php%3Faid%3D1083%23%23%23
             %2C14053232919107.jpg%7C14053233629812.jpg%7C14053233679827.jpg%7C14053233949645.jpg%2C10%u670824%u65E5
             %2014%3A50%3A40; Hm_lvt_db0f997da69f1fbbefb1983923807f95=1445669441; Hm_lpvt_db0f997da69f1fbbefb1983923807f95
             =1445669441; NPAT63435038LR_check_data=4%7C1445669563666%7C%7C%7C"."\r\n".
                     "Referer:http://www.bj-tygy.com/plus/view.php?aid=1083"."\r\n".
                     "User-Agent:Mozilla/5.0 (Windows NT 6.1; rv:41.0) Gecko/20100101 Firefox/41.0"."\r\n",
         'content' => $data
     )
 );
 $context = stream_context_create($opts);

 function getCurrentTime (){
     list ($msec,$sec) = explode(" ", microtime());
     return (float)$msec + (float)$sec;
 }

 $begin = getCurrentTime();
 for($i = 0; $i < 10; $i ++){
     $html = @file_get_contents('http://www.bj-tygy.com/plus/feedback_ajax.php?dopost=send&aid=1083', false, $context);
     echo ($i+1),$html,'<br />';
     //var_dump($http_response_header);
 }
 $end = getCurrentTime();
 $spend = $end - $begin;
 echo $spend."s\n";

这里使用了 http_build_query 方法：使用给出的关联（或下标）数组生成一个经过 URL-encode 的请求字符串。

输出：

说明发送 POST 请求成功。