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Difference between revisions of "HttpUserAgentModule"

(Created page with "# HTTP user_agent module for Tengine #syntax: user_agent $variable_name { greedy name; name [([+|-]version) | (version1~version2)] value; } if ($variable ==...")
 
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# HTTP user_agent module for Tengine
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= Syntax =
#syntax:
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user_agent $variable_name {
 
user_agent $variable_name {
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## Introduction
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== Introduction ==
  
 
nongreedy:
 
nongreedy:

Revision as of 09:39, 29 November 2012

Syntax

user_agent $variable_name {

   greedy        name;
   name [([+|-]version) | (version1~version2)]  value;

}

if ($variable == value) {

   echo hello;

}


Introduction

nongreedy: We specify the keyword in the user_agent string from right to left, and this is more efficient. As usual, we use the greedy algorithm. It will return immediately after the keyword being found.

E.g 1. "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; WOW64; Trident/6.0)", this string is MSIE's user_agent string, we will return when we find the keyword "MSIE". But the truth is not alway like this: E.g 2. "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_7_3) AppleWebKit/535.20 (KHTML, like Gecko) Chrome/19.0.1036.7 Safari/535.20", This is Chrome's user_agent. We will match Safari frist. If we define safari is greedy, it scans the string in a reverse order. If a keyword is greedy, it will not return when it matches the keyword at the first time. It will continue to scan the string.

default: set the default value of this variable;

The directive format is like this in the block: name version value;

name: the name of operating_system, browser, crawler and so on; version: It can be omitted, and it support multiple formats; value: It is the value filled to the variable;

for example:

user_agent $example {

   #set default value
   default                                             msie;
   #define safari is greedy
   greedy                                             safari;
   #match exact version
   msie                6.0                             1;
   #match interval
   msie                7.0~8.0                         2;
   #match greater than version 9.0
   msie                9.0+                            3;
   #match less than version 4.0 (include 4.0)
   msie                4.0-                            4;
   #match all
   Chrome                                              5;

}