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php://input とはどういう意味ですか?

WBOY
WBOYオリジナル
2016-06-13 13:19:501090ブラウズ

php://input是什么意思?php输入流input的介绍

PHP输入流php://input

在使用xml-rpc的时候，server端获取client数据，主要是通过php输入流input，而不是$_POST数组。所以，这里主要探讨php输入流php://input

对一php://input介绍，PHP官方手册文档有一段话对它进行了很明确地概述。

“php://input allows you to read raw POST data. It is a less memory intensive alternative to $HTTP_RAW_POST_DATA and does not need any special php.ini directives. php://input is not available with enctype=”multipart/form-data”.
翻译过来，是这样：
“php://input可以读取没有处理过的POST数据。相较于$HTTP_RAW_POST_DATA而言，它给内存带来的压力较小，并且不需要特殊的php.ini设置。php://input不能用于enctype=multipart/form-data”

我们应该怎么去理解这段概述呢?!我把它划分为三部分，逐步去理解。

  1. 读取POST数据
  2. 不能用于multipart/form-data类型
  3. php://input VS $HTTP_RAW_POST_DATA

读取POST数据

PHPer们一定很熟悉$_POST这个内置变量。$_POST与php://input存在哪些关联与区别呢?另外，客户端向服务端交互数据，最常用的方法除了POST之外，还有GET。既然php://input作为PHP输入流，它能读取GET数据吗？这二个问题正是我们这节需要探讨的主要内容。
经验告诉我们，从测试与观察中总结，会是一个很凑效的方法。这里，我写了几个脚本来帮助我们测试。 

@file 192.168.0.6:/phpinput_server.php 打印出接收到的数据
@file 192.168.0.8:/phpinput_post.php 模拟以POST方法提交表单数据
@file 192.168.0.8:/phpinput_xmlrpc.php 模拟以POST方法发出xmlrpc请求.
@file 192.168.0.8:/phpinput_get.php 模拟以GET方法提交表单表数

phpinput_server.php与phpinput_post.php 

<div class="codesnip-container">
<pre class="php codesnip"><span class="kw2"><strong><?php</strong></span>
<span class="co1"><span style="color: #808080;">//@file phpinput_server.php</span></span>
<span class="re0">$raw_post_data</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">file_get_contents</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'php://input'</span><span class="sy0">,</span> <span class="st_h">'r'</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="st0"><span style="color: #ff0000;">"-------<span class="es1">\$</span>_POST------------------<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="kw3"><span style="color: #000066;">var_dump</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$_POST</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="st0"><span style="color: #ff0000;">"-------php://input-------------<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$raw_post_data</span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="sy1">?></span>
?
<span class="kw2"><strong><?php</strong></span>
<span class="co1"><span style="color: #808080;">//@file phpinput_post.php</span></span>
<span class="re0">$http_entity_body</span> <span class="sy0">=</span> <span class="st_h">'n='</span> <span class="sy0">.</span> <span class="kw3"><span style="color: #000066;">urldecode</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'perfgeeks'</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="sy0">.</span> <span class="st_h">'&amp;p='</span> <span class="sy0">.</span> <span class="kw3"><span style="color: #000066;">urldecode</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'7788'</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="re0">$http_entity_type</span> <span class="sy0">=</span> <span class="st_h">'application/x-www-form-urlencoded'</span><span class="sy0">;</span>
<span class="re0">$http_entity_length</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">strlen</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$http_entity_body</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="re0">$host</span> <span class="sy0">=</span> <span class="st_h">'192.168.0.6'</span><span class="sy0">;</span>
<span class="re0">$port</span> <span class="sy0">=</span> <span class="nu0"><span style="color: #ff33ff;">80</span></span><span class="sy0">;</span>
<span class="re0">$path</span> <span class="sy0">=</span> <span class="st_h">'/phpinput_server.php'</span><span class="sy0">;</span>
<span class="re0">$fp</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">fsockopen</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$host</span><span class="sy0">,</span> <span class="re0">$port</span><span class="sy0">,</span> <span class="re0">$error_no</span><span class="sy0">,</span> <span class="re0">$error_desc</span><span class="sy0">,</span> 30<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">if</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"POST <span class="es4">{$path}</span> HTTP/1.1<span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Host: <span class="es4">{$host}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Content-Type: <span class="es4">{$http_entity_type}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Content-Length: <span class="es4">{$http_entity_length}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Connection: close<span class="es1">\r</span><span class="es1">\n</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="re0">$http_entity_body</span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\r</span><span class="es1">\n</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
?
  <span class="kw1"><span style="color: #a1a100;">while</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="sy0">!</span><span class="kw3"><span style="color: #000066;">feof</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span style="color: #66cc66;"><span class="br0">)</span><span class="br0">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
    <span class="re0">$d</span> <span class="sy0">.=</span> <span class="kw3"><span style="color: #000066;">fgets</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> 4096<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="br0"><span style="color: #66cc66;">}</span></span>
  <span class="kw3"><span style="color: #000066;">fclose</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$d</span><span class="sy0">;</span>
<span class="br0"><span style="color: #66cc66;">}</span></span>
<span class="sy1">?></span>

我们可以通过使用工具ngrep抓取http请求包（因为我们需要探知的是php://input，所以我们这里只抓取http Request数据包）。我们来执行测试脚本phpinput_post.php 

<span class="sy0">@</span>php <span class="sy0">/</span>phpinput_post.php
HTTP/1.1 200 OK
Date: Thu, 08 Apr 2010 03:23:36 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Content-Length: 160
Connection: close
Content-Type: text/html; charset=UTF-8
-------$_POST------------------
array(2) {
  ["n"]=> string(9) "perfgeeks"
  ["p"]=> string(4) "7788"
}
-------php://input-------------
<strong>n=perfgeeks&p=7788</strong>

通过ngrep抓到的http请求包如下: 

T 192.168.0.8:57846 -> 192.168.0.6:80 [AP]
  <strong>POST</strong> /phpinput_server.php HTTP/1.1..
  Host: 192.168.0.6..<strong>Content-Type: application/x-www-form-urlencoded</strong>..Co
  ntent-Length: 18..Connection: close....<strong>n=perfgeeks&p=7788</strong>....

仔细观察，我们不难发现
1，$_POST数据,php://input 数据与httpd entity body数据是“一致”的
2，http请求中的Content-Type是application/x-www-form-urlencoded ，它表示http请求body中的数据是使用http的post方法提交的表单数据，并且进行了urlencode()处理。
(注:注意加粗部分内容，下文不再提示). http://www.k686.com

我们再来看看脚本phpinput_xmlrpc.php的原文件内容，它模拟了一个POST方法提交的xml-rpc请求。 

<div class="codesnip-container">
<pre class="php codesnip"><span class="kw2"><strong><?php</strong></span>
<span class="co1"><span style="color: #808080;">//@file phpinput_xmlrpc.php</span></span>
<span class="re0">$http_entity_body</span> <span class="sy0">=</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\n</span><span class="es1">\n</span>   jt_userinfo<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="re0">$http_entity_type</span> <span class="sy0">=</span> <span class="st_h">'text/html'</span><span class="sy0">;</span>
<span class="re0">$http_entity_length</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">strlen</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$http_entity_body</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="re0">$host</span> <span class="sy0">=</span> <span class="st_h">'192.168.0.6'</span><span class="sy0">;</span>
<span class="re0">$port</span> <span class="sy0">=</span> <span class="nu0"><span style="color: #ff33ff;">80</span></span><span class="sy0">;</span>
<span class="re0">$path</span> <span class="sy0">=</span> <span class="st_h">'/phpinput_server.php'</span><span class="sy0">;</span>
<span class="re0">$fp</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">fsockopen</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$host</span><span class="sy0">,</span> <span class="re0">$port</span><span class="sy0">,</span> <span class="re0">$error_no</span><span class="sy0">,</span> <span class="re0">$error_desc</span><span class="sy0">,</span> 30<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">if</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"POST <span class="es4">{$path}</span> HTTP/1.1<span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Host: <span class="es4">{$host}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Content-Type: <span class="es4">{$http_entity_type}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Content-Length: <span class="es4">{$http_entity_length}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Connection: close<span class="es1">\r</span><span class="es1">\n</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="re0">$http_entity_body</span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\r</span><span class="es1">\n</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw1"><span style="color: #a1a100;">while</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="sy0">!</span><span class="kw3"><span style="color: #000066;">feof</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span style="color: #66cc66;"><span class="br0">)</span><span class="br0">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
    <span class="re0">$d</span> <span class="sy0">.=</span> <span class="kw3"><span style="color: #000066;">fgets</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> 4096<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="br0"><span style="color: #66cc66;">}</span></span>
?
  <span class="kw3"><span style="color: #000066;">fclose</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$d</span><span class="sy0">;</span>
<span class="br0"><span style="color: #66cc66;">}</span></span>
<span class="sy1">?></span>

同样地，让我们来执行这个测试脚本 

<span class="sy0">@</span>php <span class="sy0">/</span>phpinput_xmlrcp.php
HTTP/1.1 200 OK
Date: Thu, 08 Apr 2010 03:47:18 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Content-Length: 154
Connection: close
Content-Type: text/html; charset=UTF-8

-------$_POST------------------
array(0) {
}

-------php://input-------------
<strong>3fc3509638999935eead31da45711042
836a1ce07dee1c81689932e051531a60
   8a11bc632ea32a57b3e3693c7987c420jt_userinfodf406f776eecbaf16b62325323196f14
b99e2ce86b6658e0ccbb6fe0c6ff9776</strong>

执行这个脚本的时候，我们通过ngrep抓取的http请求数据包如下 

T 192.168.0.8:45570 -> 192.168.0.6:80 [AP]
  <strong>POST</strong> /phpinput_server.php HTTP/1.1..
  Host: 192.168.0.6..<strong>Content-Type: text/html</strong>..Content-Length: 75..Connec
  tion: close....<strong>3fc3509638999935eead31da45711042.836a1ce07dee1c81689932e051531a60.   8a11bc632ea32a57b3e3693c7987c420jt_userinfoeec9191ac94bf6c1da7852ad63e33a5f.b99e2ce86b6658e0ccbb6fe0c6ff9776</strong>....

同样，我样也可以很容易地发现:
1，http请求中的Content-Type是text/xml。它表示http请求中的body数据是xml数据格式。
2，服务端$_POST打印出来的是一个空数组，即与http entity body不一致了。这跟上个例子不一样了，这里的Content-Type是text/xml,而不是application/x-www-form-urlencoded
3，而php://input数据还是跟http entity body数据一致。也就是php://input数据和$_POST数据不一致了。

我们再来看看通过GET方法提交表单数据的情况，php://input能不能读取到GET方法的表单数据？在这里，我们稍加改动一下phpinput_server.php文件，将$_POST改成$_GET。 

<div class="codesnip-container">
<pre class="php codesnip"><span class="kw2"><strong><?php</strong></span>
<span class="co1"><span style="color: #808080;">//@file phpinput_server.php</span></span>
<span class="re0">$raw_post_data</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">file_get_contents</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'php://input'</span><span class="sy0">,</span> <span class="st_h">'r'</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="st0"><span style="color: #ff0000;">"-------<span class="es1">\$</span>_GET------------------<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="kw3"><span style="color: #000066;">var_dump</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$_GET</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="st0"><span style="color: #ff0000;">"-------php://input-------------<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$raw_post_data</span> <span class="sy0">.</span> <span class="st0"><span style="color: #ff0000;">"<span class="es1">\n</span>"</span></span><span class="sy0">;</span>
<span class="sy1">?></span>
?
<span class="kw2"><strong><?php</strong></span>
<span class="co1"><span style="color: #808080;">//@file phpinput_get.php</span></span>
<span class="re0">$query_path</span> <span class="sy0">=</span> <span class="st_h">'n='</span> <span class="sy0">.</span> <span class="kw3"><span style="color: #000066;">urldecode</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'perfgeeks'</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="sy0">.</span> <span class="st_h">'&amp;p='</span> <span class="sy0">.</span> <span class="kw3"><span style="color: #000066;">urldecode</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'7788'</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="re0">$host</span> <span class="sy0">=</span> <span class="st_h">'192.168.0.6'</span><span class="sy0">;</span>
<span class="re0">$port</span> <span class="sy0">=</span> <span class="nu0"><span style="color: #ff33ff;">80</span></span><span class="sy0">;</span>
<span class="re0">$path</span> <span class="sy0">=</span> <span class="st_h">'/phpinput_server.php'</span><span class="sy0">;</span>
<span class="re0">$d</span> <span class="sy0">=</span> <span class="st_h">''</span><span class="sy0">;</span>
<span class="re0">$fp</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">fsockopen</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$host</span><span class="sy0">,</span> <span class="re0">$port</span><span class="sy0">,</span> <span class="re0">$error_no</span><span class="sy0">,</span> <span class="re0">$error_desc</span><span class="sy0">,</span> 30<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">if</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"GET <span class="es4">{$path}</span>?<span class="es4">{$query_path}</span> HTTP/1.1<span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Host: <span class="es4">{$host}</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw3"><span style="color: #000066;">fputs</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> <span class="st0"><span style="color: #ff0000;">"Connection: close<span class="es1">\r</span><span class="es1">\n</span><span class="es1">\r</span><span class="es1">\n</span>"</span></span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
?
  <span class="kw1"><span style="color: #a1a100;">while</span></span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="sy0">!</span><span class="kw3"><span style="color: #000066;">feof</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span style="color: #66cc66;"><span class="br0">)</span><span class="br0">)</span></span> <span class="br0"><span style="color: #66cc66;">{</span></span>
    <span class="re0">$d</span> <span class="sy0">.=</span> <span class="kw3"><span style="color: #000066;">fgets</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="sy0">,</span> 4096<span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="br0"><span style="color: #66cc66;">}</span></span>
  <span class="kw3"><span style="color: #000066;">fclose</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$fp</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
  <span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$d</span><span class="sy0">;</span>
 <span class="br0"><span style="color: #66cc66;">}</span></span>
<span class="sy1">?></span>

同样，我们执行下一phpinput_get.php测试脚本，它模拟了一个通常情况下的GET方法提交表单数据。 

<span class="sy0">@</span>php <span class="sy0">/</span>phpinput_get.php
HTTP/1.1 200 OK
Date: Thu, 08 Apr 2010 07:38:15 GMT
Server: Apache/2.2.3 (CentOS)
X-Powered-By: PHP/5.1.6
Content-Length: 141
Connection: close
Content-Type: text/html; charset=UTF-8

-------$_GET------------------
array(2) {
  ["n"]=>
  string(9) "perfgeeks"
  ["p"]=>
  string(4) "7788"
}

-------php://input-------------

在这个时候，使用ngrep工具，捕获的相应的http请求数据包如下 

T 192.168.0.8:36775 -> 192.168.0.6:80 [AP]
  <strong>GET</strong> /phpinput_server.php?<strong>n=perfgeeks&p=7788</strong> HTTP/1.1..
  Host: 192.168.0.6..Connection: close....

比较POST方法提交的http请求，通常GET方法提交的请求中，entity body为空。同时，不会指定Content-Type和Content-Length。但是，如果强硬数据http entity body，并指明正确地Content-Type和Content-Length,那么php://input还可是读取得到http entity body数据，但不是$_GET数据。

所根据，上面几个探测，我们可以作出以下总结:
1，Content-Type取值为application/x-www-form-urlencoded时，php会将http请求body相应数据会填入到数组$_POST，填入到$_POST数组中的数据是进行urldecode()解析的结果。（其实，除了该Content-Type，还有multipart/form-data表示数据是表单数据，稍后我们介绍）
2，php://input数据，只要Content-Type不为multipart/form-data(该条件限制稍后会介绍)。那么php://input数据与http entity body部分数据是一致的。该部分相一致的数据的长度由Content-Length指定。
3，仅当Content-Type为application/x-www-form-urlencoded且提交方法是POST方法时，$_POST数据与php://input数据才是”一致”（打上引号，表示它们格式不一致，内容一致）的。其它情况，它们都不一致。
4，php://input读取不到$_GET数据。是因为$_GET数据作为query_path写在http请求头部(header)的PATH字段，而不是写在http请求的body部分。

这也帮助我们理解了，为什么xml_rpc服务端读取数据都是通过file_get_contents(‘php://input’, ‘r’)。而不是从$_POST中读取，正是因为xml_rpc数据规格是xml，它的Content-Type是text/xml。

php://input碰到了multipart/form-data

上传文件的时候，表单的写法是这样的 

<div class="codesnip-container">
<pre class="html4strict codesnip"><span class="sc2"><<span class="kw2"><strong><span style="color: #000000;">form</span></strong></span> <span class="kw3"><span style="color: #000066;">enctype</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"multipart/form-data"</span></span> <span class="kw3"><span style="color: #000066;">action</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"phpinput_server.php"</span></span> <span class="kw3"><span style="color: #000066;">method</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"POST"</span></span> ></span>
    <span class="sc2"><<span class="kw2"><strong><span style="color: #000000;">input</span></strong></span> <span class="kw3"><span style="color: #000066;">type</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"text"</span></span> <span class="kw3"><span style="color: #000066;">name</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"n"</span></span>  <span class="sy0">/</span>></span>
    <span class="sc2"><<span class="kw2"><strong><span style="color: #000000;">input</span></strong></span> <span class="kw3"><span style="color: #000066;">type</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"file"</span></span> <span class="kw3"><span style="color: #000066;">name</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"f"</span></span> <span class="sy0">/</span>></span>
    <span class="sc2"><<span class="kw2"><strong><span style="color: #000000;">input</span></strong></span> <span class="kw3"><span style="color: #000066;">type</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"submit"</span></span> <span class="kw3"><span style="color: #000066;">value</span></span><span class="sy0">=</span><span class="st0"><span style="color: #ff0000;">"upload now"</span></span> <span class="sy0">/</span>></span>
<span class="sc2"><<span class="sy0">/</span><span class="kw2"><strong><span style="color: #000000;">form</span></strong></span>></span>

那么，enctype=multipart/form-data这里的意义，就是将该次http请求头部(head)中的Content-Type设置为multipart/form-data。请查阅RFC1867对它的描述。multipart/form-data也表示以POST方法提交表单数据，它还伴随了文件上传，所以会跟application/x-www-form-urlencoded数据格式不一样。它会以一更种更合理的，更高效的数据格式传递给服务端。我们提交该表单数据，并且打印出响应结果，如下: 

-------$_POST------------------
array(1) { ["n"]=> string(9) "perfgeeks" }
-------php://input-------------

同时，我们通过ngrep抓取的相应的http请求数据包如下: 

########
T 192.168.0.8:3981 -> 192.168.0.6:80 [AP]
 <strong> POST</strong> /phpinput_server.php HTTP/1.1..Host: 192.168.0.6..Connection: kee
  p-alive..User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US) A
  ppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.3 Safari/533.2..Re
  ferer: http://192.168.0.6/phpinput_server.php..Content-Length: 306..Ca
  che-Control: max-age=0..Origin: http://192.168.0.6..<strong>Content-Type: mult
  ipart/form-data; boundary=----WebKitFormBoundarybLQwkp4opIEZn1fA</strong>..Acce
  pt: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q
  =0.8,image/png,*/*;q=0.5..Accept-Encoding: gzip,deflate,sdch..Accept-L
  anguage: zh-CN,zh;q=0.8..Accept-Charset: GBK,utf-8;q=0.7,*;q=0.3..Cook
  ie: SESS3b0e658f87cf58240de13ab43a399df6=lju6o5bg8u04lv1ojugm2ccic6...
  .
##
T 192.168.0.8:3981 -> 192.168.0.6:80 [AP]
  ------WebKitFormBoundarybLQwkp4opIEZn1fA..Content-Disposition: form-da
  ta; <strong>name="n"....perfgeeks</strong>..------WebKitFormBoundarybLQwkp4opIEZn1fA..C
  ontent-Disposition: form-data; <strong>name="f"; filename="test.txt"..Content-
  Type: text/plain....i am file</strong>..multipart/form-data..------WebKitFormBo
  undarybLQwkp4opIEZn1fA--..
##

从响应输出来比对，$_POST数据跟请求提交数据相符，即$_POST = array(‘n’ => ‘perfgeeks’)。这也跟http请求body中的数据相呼应，同时说明PHP把相应的数据填入$_POST全局变量。而php://input输出为空，没有输出任何东西，尽管http请求数据包中body不为空。这表示，当Content-Type为multipart/form-data的时候，即便http请求body中存在数据，php://input也为空，PHP此时，不会把数据填入php://input流。所以，可以确定: php://input不能用于读取enctype=multipart/form-data数据。

我们再比较这次通过ngrep抓取的http请求数据包，我们会发现，最大不同的一点是Content-Type后面跟了boundary定义了数据的分界符，bounday是随机生成的。另外一个大不一样的，就是http entity body中的数据组织结构不一样了。

上一节，我们概述了，当Content-Type为application/x-www-form-urlencoded时，php://input和$_POST数据是“一致”的，为其它Content-Type的时候，php://input和$_POST数据数据是不一致的。因为只有在Content-Type为application/x-www-form-urlencoded或者为multipart/form-data的时候，PHP才会将http请求数据包中的body相应部分数据填入$_POST全局变量中,其它情况PHP都忽略。而php://input除了在数据类型为multipart/form-data之外为空外，其它情况都可能不为空。通过这一节，我们更加明白了php://input与$_POST的区别与联系。所以，再次确认，php://input无法读取enctype=multipart/form-data数据，当php://input遇到它时，永远为空，即便http entity body有数据。

php://input VS $http_raw_post_data

相信大家对php://input已经有一定深度地了解了。那么$http_raw_post_data是什么呢？$http_raw_post_data是PHP内置的一个全局变量。它用于，PHP在无法识别的Content-Type的情况下，将POST过来的数据原样地填入变量$http_raw_post_data。它同样无法读取Content-Type为multipart/form-data的POST数据。需要设置php.ini中的always_populate_raw_post_data值为On，PHP才会总把POST数据填入变量$http_raw_post_data。

把脚本phpinput_server.php改变一下，可以验证上述内容 

<div class="codesnip-container">
<pre class="php codesnip"><span class="kw2"><strong><?php</strong></span>
<span class="re0">$raw_post_data</span> <span class="sy0">=</span> <span class="kw3"><span style="color: #000066;">file_get_contents</span></span><span class="br0"><span style="color: #66cc66;">(</span></span><span class="st_h">'php://input'</span><span class="sy0">,</span> <span class="st_h">'r'</span><span class="br0"><span style="color: #66cc66;">)</span></span><span class="sy0">;</span>
<span class="re0">$rtn</span> <span class="sy0">=</span> <span class="br0"><span style="color: #66cc66;">(</span></span><span class="re0">$raw_post_data</span> <span class="sy0">==</span> <span class="re0">$HTTP_RAW_POST_DATA</span><span class="br0"><span style="color: #66cc66;">)</span></span> ? 1 <span class="sy0">:</span> <span class="nu0"><span style="color: #ff33ff;">0</span></span><span class="sy0">;</span>
<span class="kw1"><span style="color: #a1a100;">echo</span></span> <span class="re0">$rtn</span><span class="sy0">;</span>
<span class="sy1">?></span>

执行测试脚本 

<span class="sy0">@</span>php phpinput_post.php
<span class="sy0">@</span>php phpinput_get.php
<span class="sy0">@</span>php phpinput_xmlrpc.php

得出的结果输出都是一样的，即都为1，表示php://input和$HTTP_RAW_POST_DATA是相同的。至于对内存的压力，我们这里就不做细致地测试了。有兴趣的，可以通过xhprof进行测试和观察。

これにより、このセクションは次のように要約できます:
1、php://input は http エンティティ本体で指定された長さの値を読み取ることができ、長さは Content-Length によって指定されます。データが届く POST または GET メソッドによって送信されます。ただし、通常、GET メソッドがデータを送信するとき、http リクエスト エンティティの本体部分は空です。
2. php://input と $HTTP_RAW_POST_DATA で読み取られるデータは、Content-Type が multipart/form-data ではないデータのみを読み取ります。

学習ノート

1. PHP は、Coentent-Type の値が application/x-www-data-urlencoded および multipart/form-data の場合にのみ、http リクエスト パケット内の対応するデータをグローバル変数 $ に書き込みます。 >2、PHP が Content-Type タイプを認識できない場合、http リクエスト パッケージ内の対応するデータは変数 $HTTP_RAW_POST_DATA
3、?Coentent-Type が multipart/form-data ではない場合のみ、PHP http リクエスト パケット内の対応するデータを php://input に埋め込みません。それ以外の場合は、他の状況でも同じになります。 Coentent-Length で指定されるパディングの長さ。
4. Content-Type が application/x-www-data-urlencoded の場合のみ、php://input データは $_POST データと一致します。
5. php://input データは常に $HTTP_RAW_POST_DATA と同じですが、php://input は $HTTP_RAW_POST_DATA より効率的であり、php.ini での特別な設定は必要ありません。
6. PATH フィールド query_path 部分には、グローバル変数 $_GET を入力します。通常、GET メソッドによって送信される http リクエストの本文は空です。

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