Php $ _ SERVER ['HTTP _ USER_AGENT '] usage

In php, HTTP_USER_AGENT is used to obtain user information, including the user's browser, operating system engineering, and whether the alex toolbar is installed. For more information, see.

1. When a user accesses the SERVER, use the PHP super global variable $ _ SERVER array field ['HTTP _ USER_AGENT '] To obtain all information of the user

The Code is as follows:	Copy code
<? Php Echo $ _ SERVER ['HTTP _ USER_AGENT ']; ?>

Output result

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0;. net clr 2.0.50727; InfoPath.2; AskTbPTV/5.17.0.25589; Alexa Toolbar)

2. Use regular expressions to match the preceding strings and users' browser operating system information

3. PHP allocates the necessary CSS files, JS files, and so on based on the matched string (the user's browser operating system information... Return to user

My browser operating system information
Browser: Google Chrome 5.0

Platform: Windows 7

The Code is as follows:

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<? Php // Display the browser information of the visitor Echo 'browser: '. determinebrowser ($ Agent).' <BR> '; // Display the operating system platform used to access the user Echo 'Platform: '. determineplatform ($ Agent).' <BR> '; // Parse a positive expression against the string in $ _ SERVER ['HTTP _ USER_AGENT '] to obtain information about the browser used to access the user Function determinebrowser ($ Agent ){ $ Browseragent = ""; // Browser $ Browserversion = ""; // browser version If (ereg ('msie ([0-9]. [0-9] {1, 2}) ', $ Agent, $ version )){ $ Browserversion = $ version [1]; $ Browseragent = "Internet Explorer "; } Else if (ereg ('Opera/([0-9] {1, 2}. [0-9] {1, 2}) ', $ Agent, $ version )){ $ Browserversion = $ version [1]; $ Browseragent = "Opera "; } Else if (ereg ('Firefox/([0-9.] {1, 5}) ', $ Agent, $ version )){ $ Browserversion = $ version [1]; $ Browseragent = "Firefox "; } Else if (ereg ('chrome/([0-9.] {1, 3}) ', $ Agent, $ version )){ $ Browserversion = $ version [1]; $ Browseragent = "Chrome "; } Else if (ereg ('safari/([0-9.] {1, 3}) ', $ Agent, $ version )){ $ Browseragent = "Safari "; $ Browserversion = ""; } Else { $ Browserversion = ""; $ Browseragent = "Unknown "; } Return $ browseragent. "". $ browserversion; } // Obtain the information of the browser used to access the user. Function determineplatform ($ Agent ){ $ Browserplatform = ''; If (eregi ('win', $ Agent) & strpos ($ Agent, '95 ')){ $ Browserplatform = "Windows 95 "; } Elseif (eregi ('win 9x', $ Agent) & strpos ($ Agent, '4. 90 ')){ $ Browserplatform = "Windows ME "; } Elseif (eregi ('win', $ Agent) & ereg ('98 ', $ Agent )){ $ Browserplatform = "Windows 98 "; } Elseif (eregi ('win', $ Agent) & eregi ('nt 5.0 ', $ Agent )){ $ Browserplatform = "Window 2000 "; } Elseif (eregi ('win', $ Agent) & eregi ('nt 5.1 ', $ Agent )){ $ Browserplatform = "Windows XP "; } Elseif (eregi ('win', $ Agent) & eregi ('nt 6.0 ', $ Agent )){ $ Browserplatform = "Windows Vista "; } Elseif (eregi ('win', $ Agent) & eregi ('nt 6.1 ', $ Agent )){ $ Browserplatform = "Windows 7 "; } Elseif (eregi ('win', $ Agent) & ereg ('32', $ Agent )){ $ Browserplatform = "Windows 32 "; } Elseif (eregi ('win', $ Agent) & eregi ('nt ', $ Agent )){ $ Browserplatform = "Windows NT "; } Elseif (eregi ('mac OS ', $ Agent )){ $ Browserplatform = "Mac OS "; } Elseif (eregi ('linux ', $ Agent )){ $ Browserplatform = "Linux "; } Elseif (eregi ('unix ', $ Agent )){ $ Browserplatform = "Unix "; } Elseif (eregi ('sun', $ Agent) & eregi ('OS', $ Agent )){ $ Browserplatform = "SunOS "; } Elseif (eregi ('ibm ', $ Agent) & eregi (' OS ', $ Agent )){ $ Browserplatform = "ibm OS/2 "; } Elseif (eregi ('mac', $ Agent) & eregi ('pc', $ Agent )){ $ Browserplatform = "Macintosh "; } Elseif (eregi ('powerpc', $ Agent )){ $ Browserplatform = "PowerPC "; } Elseif (eregi ('Aix ', $ Agent )){ $ Browserplatform = "AIX "; } Elseif (eregi ('hpux ', $ Agent )){ $ Browserplatform = "HPUX "; } Elseif (eregi ('netsd', $ Agent )){ $ Browserplatform = "NetBSD "; } Elseif (eregi ('bsd', $ Agent )){ $ Browserplatform = "BSD "; } Elseif (ereg ('oss1', $ Agent )){ $ Browserplatform = "OSF1 "; } Elseif (ereg ('irix ', $ Agent )){ $ Browserplatform = "IRIX "; } Elseif (eregi ('freebsd ', $ Agent )){ $ Browserplatform = "FreeBSD "; } If ($ browserplatform = '') {$ browserplatform =" Unknown ";} Return $ browserplatform; } ?>

The specific procedure for determining the browser language is as follows:

The Code is as follows:

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<? Php $ Lang = substr ($ _ SERVER ['HTTP _ ACCEPT_LANGUAGE '], 0, 4); // only the first four digits are used to determine the preferred language. If the first five digits are obtained, en and zh may occur, affecting the judgment. If (preg_match ("/zh-c/I", $ lang )) Echo "simplified Chinese "; Else if (preg_match ("/zh/I", $ lang )) Echo "fan? Chinese "; Else if (preg_match ("/en/I", $ lang )) Echo "English "; Else if (preg_match ("/fr/I", $ lang )) Echo "French "; Else if (preg_match ("/de/I", $ lang )) Echo "German "; Else if (preg_match ("/jp/I", $ lang )) Echo "Japan "; Else if (preg_match ("/ko/I", $ lang )) Echo "Korean "; Else if (preg_match ("/es/I", $ lang )) Echo "Spanish "; Else if (preg_match ("/sv/I", $ lang )) Echo "Swedish "; Else echo $ _ SERVER ["HTTP_ACCEPT_LANGUAGE"]; ?>

To determine the browser type, analyze the content of _ SERVER ["HTTP_USER_AGENT"]. To analyze the browser language, analyze _ SERVER ["HTTP_ACCEPT_LANGUAGE"].