Header information is very important. Two people, one is a server, and the other is a browser (client). There are two headers, request header information, and response header information.
If you use PHP to obtain the header information, the server can use $ _ server,CodeAs follows:
<? Phpfunction getheaderinfo () {foreach ($ _ server as $ name => $ value) {$ headers [$ name] = $ value;} return $ headers ;} var_dump (getheaderinfo ();?>
Output:
Array (size = 32) 'HTTP _ host' => string 'localhost' (length = 9) 'HTTP _ user_agent '=> string 'mozilla/5.0 (Windows NT 5.1; RV: 20.0) Gecko/20100101 Firefox/20.0 '(length = 65) 'HTTP _ Accept' => string 'text/html, application/XHTML + XML, application/XML; Q = 0.9, */*; q = 0.8 '(length = 63) 'HTTP _ accept_language' => string 'zh-CN, ZH; q = 0.8, en-us; Q = 0.5, en; q = 0.3 '(length = 35) 'HTTP _ accept_encoding' => string 'gzip, deflate' (length = 13) 'http _ cookies' => string 'bdshare _ firstime = 100' (length = 30) 'HTTP _ connection' => string 'keep-alive' (length = 10) 'http _ cache_control '=> string 'max-age = 0' (length = 9) 'path' => string 'C: \ windows \ system32; C: \ windows; c: \ windows \ system32 \ WBEM; D: \ SVN \ bin; D: \ curl-7.19.5; E: \ mysql5.5 \ mysql \ bin; C: \ Program Files \ mysql server 5.5 \ bin; C: \ ruby193 \ bin; C: \ Program Files \ sinovoice \ jtts 5.0 Desktop \ bin; D: \ PHP \ XAMPP \ PHP; C: \ Wamp \ bin \ PHP \ php5.4.3 \ php.exe; '(length = 266) 'systemroot' => string 'C: \ Windows '(length = 10) 'comspec' => string 'C: \ windows \ system32 \ cmd.exe '(length = 27) 'pathext' => string '. com ;. EXE ;. BAT ;. CMD ;. vbs ;. VBE ;. JS ;. JSE ;. WSF ;. wsh' (length = 48) 'windir' => string 'C: \ Windows' (length = 10) 'server _ signature '=> string ''(length = 0) 'server _ soft' => string 'apache/2.2.22 (win32) PHP/5.4.3 '(length = 31) 'server _ name' => string 'localhost' (length = 9) 'server _ ADDR '=> string' 127. 0.0.1 '(length = 9) 'server _ port' => string '80' (length = 2) 'remote _ ADDR' => string '127. 0.0.1 '(length = 9) 'document _ root' => string 'C:/Wamp/www/' (length = 12) 'server _ admin' => string 'admin @ localhost' (length = 15) 'script _ filename' => string 'C:/Wamp/www/1. PHP '(length = 17) 'remote _ port' => string '20140901' (length = 4) 'Gateway _ interface' => string 'cgi/123' (length = 7) 'server _ Protocol' => string 'HTTP/123' (length = 8) 'request _ method' => string 'get' (length = 3) 'query _ string' => string ''(length = 0) 'request _ URI '=> string'/1. PHP '(length = 6) 'script _ name' => string'/1. PHP '(length = 6) 'php _ Self' => string '/1. PHP '(length = 6) 'request _ time_float' => float 1366034246.187 'request _ time' => int 1366034246
We can see that not only some information about the client is output, but also some information about the server. For the specific role of this information, here is not much introduction, please refer to the http://www.cnblogs.com/IAmBetter/archive/2013/04/11/3014796.html
In fact, the following functions can be used for Apache servers:Getallheaders(). The benefits of using this function are not mentioned much. Let's look at the return value directly.
Array (size = 8) 'host' => string 'localhost' (length = 9) 'user-agent' => string 'mozilla/5.0 (Windows NT 5.1; RV: 20.0) Gecko/20100101 Firefox/20.0 '(length = 65) 'access' => string 'text/html, application/XHTML + XML, application/XML; q = 0.9, */*; q = 0.8 '(length = 63) 'Accept-color' => string 'zh-CN, ZH; q = 0.8, en-US; q = 0.5, en; q = 0.3 '(length = 35) 'Accept-encoding' => string 'gzip, deflate' (length = 13) 'cookies' => string 'bdshare _ firstime = 1365907820098 '(length = 30) 'connection' => string 'keep-alive' (length = 10) 'cache-control' => string 'max-age = 0' (length = 9)
There are no parameters similar to HTTP _, and you still need to handle them.
If you know how to obtain the request header information, you should also know how to set the header information, such:
<? Phpheader ("Name: anleb");?>
The client obtains the header information set by the server. [name]
So what is the purpose of this? Actually, is there a way to determine what request the other party is? Is it a synchronous request or an asynchronous request?
2.html page: Request page
<HTML>
Back to page
<? Phpif (isset (getallheaders () ['is _ Ajax ']) & getallheaders () ['is _ Ajax'] = 'yes') {echo 'yes ';} else {echo 'no';}?>
Result:
Sorry.