Conversion between Utf-8 and GB2312

Some codes about conversion between utf-8 and gb2312 when handling different text format.

// ChineseCodeLib.h: interface for the CChineseCodeLib class.
//
//////////////////////////////////////////////////////////////////////
#include<string>
using namespace std;

/*
功?能?：?汉?字?GB2312与?UTF-8编?码?互?转?
作?者?：?litz
Email:mycro@163.com
参?考?：?吴?康?彬?先?生?的?文?章?《?UTF-8与?GB2312之?间?的?互?换?》?
http://www.vckbase.com/document/viewdoc/?id=1397
*/


#if !defined(__CCHINESECODELIB_H_)
#define __CCHINESECODELIB_H_


class CChineseCodeLib  
{
public:
    static void UTF_8ToGB2312(string& pOut,char *pText, int pLen);
    static void GB2312ToUTF_8(string& pOut,char *pText, int pLen);
    // Unicode 转?换?成?UTF-8
    static void UnicodeToUTF_8(char* pOut,wchar_t* pText);
    // GB2312 转?换?成?　?Unicode
    static void Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer);
    // 把?Unicode 转?换?成?GB2312
    static void UnicodeToGB2312(char* pOut,unsigned short uData);
    // 把?UTF-8转?换?成?Unicode
    static void UTF_8ToUnicode(wchar_t* pOut,char* pText);

    CChineseCodeLib();
    virtual ~CChineseCodeLib();
};

#endif // !defined(__CCHINESECODELIB_H_)

///////////////////////////////////////////////////

// ChineseCodeLib.cpp: implementation of the CChineseCodeLib class.
//
//////////////////////////////////////////////////////////////////////

#include <stdio.h>
#include <tchar.h>
#include <windows.h>
#include "ChineseCodeLib.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CChineseCodeLib::CChineseCodeLib()
{

}

CChineseCodeLib::~CChineseCodeLib()
{

}


void CChineseCodeLib::UTF_8ToUnicode(wchar_t* pOut,char *pText)
{
    char* uchar = (char *)pOut;
    
    uchar[1] = ((pText[0] & 0x0F) << 4) + ((pText[1] >> 2) & 0x0F);
    uchar[0] = ((pText[1] & 0x03) << 6) + (pText[2] & 0x3F);

    return;
}

void CChineseCodeLib::UnicodeToGB2312(char* pOut,unsigned short uData)
{
    WideCharToMultiByte(CP_ACP,NULL,(LPCWSTR)&uData,1,pOut,sizeof(wchar_t),NULL,NULL);
    return;
}

void CChineseCodeLib::Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer)
{
    ::MultiByteToWideChar(CP_ACP,MB_PRECOMPOSED,gbBuffer,2,pOut,1);
    return;
}

void CChineseCodeLib::UnicodeToUTF_8(char* pOut,wchar_t* pText)
{
    // 注?意?wchar_t高?低?字?的?顺?序?,低?字?节?在?前?，?高?字?节?在?后?
    char* pchar = (char *)pText;

    pOut[0] = (0xE0 | ((pchar[1] & 0xF0) >> 4));
    pOut[1] = (0x80 | ((pchar[1] & 0x0F) << 2)) + ((pchar[1] & 0xC0) >> 6);
    pOut[2] = (0x80 | (pchar[0] & 0x3F));
    
    return;
}

void CChineseCodeLib::GB2312ToUTF_8(string& pOut,char *pText, int pLen)
{
    char buf[4];
    char* rst = new char[pLen + (pLen >> 2) + 2];
    
    memset(buf,0,4);
    memset(rst,0,pLen + (pLen >> 2) + 2);
    
    int i = 0;
    int j = 0;    
    while(i < pLen)
    {
        //如?果?是?英?文?直?接?复?制?就?可?以?
        if( *(pText + i) >= 0)
        {
            rst[j++] = pText[i++];
        }
        else
        {
            wchar_t pbuffer;
            Gb2312ToUnicode(&pbuffer,pText+i);
            
            UnicodeToUTF_8(buf,&pbuffer);
            
            unsigned short int tmp = 0;
            tmp = rst[j] = buf[0];
            tmp = rst[j+1] = buf[1];
            tmp = rst[j+2] = buf[2];
            
            
            j += 3;
            i += 2;
        }
    }
    rst[j] = '\0';

    //返?回?结?果?
    pOut = rst;        
    delete []rst;    
    
    return;
}

void CChineseCodeLib::UTF_8ToGB2312(string &pOut, char *pText, int pLen)
{
     char * newBuf = new char[pLen];
     char Ctemp[4];
     memset(Ctemp,0,4);

     int i =0;
     int j = 0;
     
     while(i < pLen)
     {
         if(pText[i] > 0)
        {
            newBuf[j++] = pText[i++];            
        }
        else                 
        {
            wchar_t Wtemp;
            UTF_8ToUnicode(&Wtemp,pText + i);
        
            UnicodeToGB2312(Ctemp,Wtemp);
            
            newBuf[j] = Ctemp[0];
            newBuf[j + 1] = Ctemp[1];

            i += 3;    
            j += 2;   
        }
     }
     newBuf[j] = '\0';
     
     pOut = newBuf;
     delete []newBuf;
     
     return; 
}

///////////////////////////////////////////////////

//A test main program:

//Input utf.txt in the same folder with the source files.

//Output resutl.txt

// Decode1.cpp : Defines the entry point for the console application.


#include "ChineseCodeLib.h"

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

#define LEN 100000

char str[LEN];
string res;


int main(int argc, char* argv[])
{
    ifstream fin("utf.txt");
    ofstream fout("result.txt");

    while(!fin.eof())
    {
        fin.getline(str,LEN);
        if(strlen(str)<10)
            continue;
        CChineseCodeLib::UTF_8ToGB2312(res,str,strlen(str));
        //cout<<res<<endl;
        fout<<res;
    }

    fin.close();
    fout.close();

    return 0;
}

From: http://blog.csdn.net/Mycro/archive/2005/12/06/544637.aspx