C # analyze the search engine url to get the search keyword

The following uses the C # language as an example:

Using System;
Using System. Collections. Generic;
Using System. Text;
Using System. Text. RegularExpressions;

Namespace Util
{
Public class SearchKeyword
{
Public SearchKeyword (){}

// Search Engine Features
Private string [] [] _ Enginers = new string [] []
{
New string [] {"google", "utf8", "q "},
New string [] {"baidu", "gb2312", "wd "},
New string [] {"yahoo", "utf8", "p "},
New string [] {"yisou", "utf8", "search "},
New string [] {"live", "utf8", "q "},
New string [] {"tom", "gb2312", "word "},
New string [] {"163", "gb2312", "q "},
New string [] {"iask", "gb2312", "k "},
New string [] {"soso", "gb2312", "w "},
New string [] {"sogou", "gb2312", "query "},
New string [] {"zhongsou", "gb2312", "w "},
New string [] {"3721", "gb2312", "p "},
New string [] {"openfind", "utf8", "q "},
New string [] {"alltheweb", "utf8", "q "},
New string [] {"lycos", "utf8", "query "},
New string [] {"onseek", "utf8", "q "},
New string [] {"youdao", "utf8", "q "},
New string [] {"bing", "utf8", "q "},
New string [] {"118114", "gb2312", "kw "}
};
// Search engine name
Private string _ EngineName = "";
Public string EngineName
{
Get
{
Return _ EngineName;
}
}
// Search engine Encoding
Private string _ Coding = "utf8 ″;
Public string Coding
{
Get
{
Return _ Coding;
}
}
// Search engine keyword query parameter name
Private string _ RegexWord = "";
Public string RegexWord
{
Get
{
Return _ RegexWord;
}
}

Private string _ Regex = @ "(";

// Search engine keyword
// Create a regular expression for the Search Keyword
Public void EngineRegEx (string myString)
{
For (int I = 0, j = _ Enginers. Length; I <j; I ++)
{
If (myString. Contains (_ Enginers [I] [0])
{
_ EngineName = _ Enginers [I] [0];
_ Coding = _ Enginers [I] [1];
_ RegexWord = _ Enginers [I] [2];
_ Regex + = _ EngineName + @ ". + .*[? /&] "+ _ RegexWord + @" [=:]) (? <Key> [^ &] *) ";
Break;
}
}
}
// Obtain the search engine keyword
Public string SearchKey (string myString)
{
EngineRegEx (myString. ToLower ());
If (_ EngineName! = "")
{
Regex myReg = new Regex (_ Regex, RegexOptions. IgnoreCase );
Match matche = myReg. Match (myString );
MyString = matche. Groups ["key"]. Value;
// + With spaces
MyString = myString. Replace ("+ ","");
If (_ Coding = "gb2312 ″)
{
MyString = GetUTF8String (myString );
}
Else
{
MyString = Uri. UnescapeDataString (myString );
}
}
Return myString;
}
// Complete Transcoding
Public string GetUTF8String (string myString)
{
Regex myReg = new Regex ("(? <Key> %...) ", RegexOptions. IgnoreCase );
MatchCollection matches = myReg. Matches (myString );
String myWord;
For (int I = 0, j = matches. Count; I <j; I ++)
{
MyWord = matches [I]. Groups ["key"]. Value. ToString ();
MyString = myString. Replace (myWord, GB2312ToUTF8 (myWord ));
}
Return myString;
}
// Convert the single word GB2312 to UTF8 URL Encoding
Public string GB2312ToUTF8 (string myString)
{
String [] myWord = myString. Split ('% ');
Byte [] myByte = new byte [] {Convert. ToByte (myWord [1], 16), Convert. ToByte (myWord [2], 16 )};
Encoding GB = Encoding. GetEncoding ("GB2312 ″);
Encoding U8 = Encoding. UTF8;
MyByte = Encoding. Convert (GB, U8, myByte );
Char [] Chars = new char [U8.GetCharCount (myByte, 0, myByte. Length)];
U8.GetChars (myByte, 0, myByte. Length, Chars, 0 );
Return new string (Chars );
}

// Judge whether it is a search engine crawler and return its type
Public string isCrawler (string SystemInfo)
{
String [] BotList = new string [] {"Google", "Baidu", "yisou", "MSN", "Yahoo", "live ",

"Tom", "163", "TMCrawler", "iask", "Sogou", "soso", "youdao", "zhongsou", "3721", "openfind ", "alltheweb", "lycos", "bing", "118114 ″};
Foreach (string Bot in BotList)
{
If (SystemInfo. ToLower (). Contains (Bot. ToLower ()))
{
Return Bot;
}
}
Return "null ";
}

Public bool IsSearchEnginesGet (string str)
{
String [] strArray = new string [] {"Google", "Baidu", "yisou", "MSN", "Yahoo", "live", "tom"

, "163", "TMCrawler", "iask", "Sogou", "soso", "youdao", "zhongsou", "3721", "openfind ", "alltheweb", "lycos", "bing", "118114 ″};
Str = str. ToLower ();
For (int I = 0; I <strArray. Length; I ++)
{
If (str. IndexOf (strArray [I]. ToLower ()> = 0)
{
Return true;
}
}
Return false;
}
}
} Call method: // obtain the source url string url = HttpContext. current. request. urlReferrer. toString (); Pkjg. util. searchKeyword searchkey = new Pkjg. util. searchKeyword (); // determines whether the search engine link if (searchkey. isSearchEnginesGet (url) {// obtain the search Keyword string Keyword = Searchkey. SearchKey (url );// Obtain the search Engine name string Engine = Searchkey. EngineName;}