字符串处理 - ANSI - Unicode - UTF8 转换

最近发现一个比较全的字符串编码转换的方法，记录如下：

2008-11-4: 使用MultiByteToWideChar和WideCharToMultiByte写的4个ANSI <-> Unicode <-> UTF-8 相互转换的函数。2008-11-5: 使用C语言标准库mbstowcs和wcstombs写的w2m和m2w两个函数，分别对应ANSI <-> Unicode 相互转换。2008-11-8: 包装一下 ANSI <-> UTF-8 。#include <stdio.h>#include <windows.h>#include <locale.h>#define BUFF_SIZE 1024wchar_t * ANSIToUnicode( const char* str ){     int textlen ;     wchar_t * result;     textlen = MultiByteToWideChar( CP_ACP, 0, str,-1, NULL,0 );      result = (wchar_t *)malloc((textlen+1)*sizeof(wchar_t));      memset(result,0,(textlen+1)*sizeof(wchar_t));      MultiByteToWideChar(CP_ACP, 0,str,-1,(LPWSTR)result,textlen );      return result; }char * UnicodeToANSI( const wchar_t* str ){     char* result;     int textlen;     textlen = WideCharToMultiByte( CP_ACP, 0, str, -1, NULL, 0, NULL, NULL );     result =(char *)malloc((textlen+1)*sizeof(char));     memset( result, 0, sizeof(char) * ( textlen + 1 ) );     WideCharToMultiByte( CP_ACP, 0, str, -1, result, textlen, NULL, NULL );     return result;}wchar_t * UTF8ToUnicode( const char* str ){     int textlen ;     wchar_t * result;     textlen = MultiByteToWideChar( CP_UTF8, 0, str,-1, NULL,0 );      result = (wchar_t *)malloc((textlen+1)*sizeof(wchar_t));      memset(result,0,(textlen+1)*sizeof(wchar_t));      MultiByteToWideChar(CP_UTF8, 0,str,-1,(LPWSTR)result,textlen );      return result; }char * UnicodeToUTF8( const wchar_t* str ){     char* result;     int textlen;     textlen = WideCharToMultiByte( CP_UTF8, 0, str, -1, NULL, 0, NULL, NULL );     result =(char *)malloc((textlen+1)*sizeof(char));     memset(result, 0, sizeof(char) * ( textlen + 1 ) );     WideCharToMultiByte( CP_UTF8, 0, str, -1, result, textlen, NULL, NULL );     return result;}/*宽字符转换为多字符Unicode - ANSI*/char* w2m(const wchar_t* wcs){      int len;      char* buf;      len =wcstombs(NULL,wcs,0);      if (len == 0)          return NULL;      buf = (char *)malloc(sizeof(char)*(len+1));      memset(buf, 0, sizeof(char) *(len+1));      len =wcstombs(buf,wcs,len+1);      return buf;}/*多字符转换为宽字符ANSI - Unicode*/wchar_t* m2w(const char* mbs){      int len;      wchar_t* buf;      len =mbstowcs(NULL,mbs,0);      if (len == 0)          return NULL;      buf = (wchar_t *)malloc(sizeof(wchar_t)*(len+1));      memset(buf, 0, sizeof(wchar_t) *(len+1));      len =mbstowcs(buf,mbs,len+1);      return buf;}char* ANSIToUTF8(const char* str){     return UnicodeToUTF8(ANSIToUnicode(str));}char* UTF8ToANSI(const char* str){     return UnicodeToANSI(UTF8ToUnicode(str));}int main(){     /*使用wcstombs和mbstowcs之前必须调用setlocale，以便决定内码*/     setlocale(LC_ALL,".936");     /*假定有一个Unicode(UTF-16LE)编码的文件，将其打开，重新编码为ANSI，写入aa.txt中，再继续编码回Unicode，写入aw.txt中*/     /*如果不存在a.txt文件，则程序出错，没有做错误处理*/     char* filename = "a.txt";     char* filenamea = "aa.txt";     char* filenamew = "aw.txt";     FILE*     input=fopen( filename, "rb");      FILE*     inputa=fopen( filenamea, "wb");      FILE*     inputw=fopen( filenamew, "wb");      wchar_t * buf ;     /*BOE设置，UTF-16LE的BOE为FEFF，如果不先将其读取出来，wcstombs会调用失败*/     fgetwc(input);     fputwc(0xFEFF,inputw);     /*开始读取文件*/     while(!feof(input))     {        buf = (wchar_t *)malloc(sizeof(wchar_t)*BUFF_SIZE)         ;        memset(buf,    0, sizeof(wchar_t) * BUFF_SIZE );        fgetws(buf,    BUFF_SIZE,    input);        fputs(w2m(buf),    inputa);        fputws(m2w(w2m(buf)),    inputw);     }     /*后续处理*/     fclose(input);     fclose(inputa);     fclose(inputw);     free(buf);     return 0;}

感谢：http://hi.baidu.com/end2012/blog/item/9ff286df5d57bc53cdbf1ab9.html