linux&windows utf8和gbk编码识别&互相转换

linux默认是utf8编码，Windows默认是gbk编码，linux系统下可用locale命令查看系统编码。

linux下使用iconv命令转换文件编码

iconv -f 源编码 -t 目标编码 1.txt > 2.txt

如 gbk转utf8

iconv -f gbk -t utf8 1.txt > 2.txt

2.txt是转换完的文件，如覆盖源文件，去掉>2,txt即可

utf8和gbk编码判定

转自csdn博客http://m.blog.csdn.net/thedarkfairytale/article/details/73457200

utf8编码

bool is_str_utf8(const char* str){    unsigned int nBytes = 0;//UFT8可用1-6个字节编码,ASCII用一个字节      unsigned char chr = *str;    bool bAllAscii = true;    for (unsigned int i = 0; str[i] != '\0'; ++i){        chr = *(str + i);        //判断是否ASCII编码,如果不是,说明有可能是UTF8,ASCII用7位编码,最高位标记为0,0xxxxxxx         if (nBytes == 0 && (chr & 0x80) != 0){            bAllAscii = false;        }        if (nBytes == 0) {            //如果不是ASCII码,应该是多字节符,计算字节数              if (chr >= 0x80) {                if (chr >= 0xFC && chr <= 0xFD){                    nBytes = 6;                }                else if (chr >= 0xF8){                    nBytes = 5;                }                else if (chr >= 0xF0){                    nBytes = 4;                }                else if (chr >= 0xE0){                    nBytes = 3;                }                else if (chr >= 0xC0){                    nBytes = 2;                }                else{                    return false;                }                nBytes--;            }        }        else{            //多字节符的非首字节,应为 10xxxxxx             if ((chr & 0xC0) != 0x80){                return false;            }            //减到为零为止            nBytes--;        }    }    //违返UTF8编码规则     if (nBytes != 0)  {        return false;    }    if (bAllAscii){ //如果全部都是ASCII, 也是UTF8        return true;    }    return true;}

gbk编码

bool is_str_gbk(const char* str){    unsigned int nBytes = 0;//GBK可用1-2个字节编码,中文两个 ,英文一个     unsigned char chr = *str;    bool bAllAscii = true; //如果全部都是ASCII,      for (unsigned int i = 0; str[i] != '\0'; ++i){        chr = *(str + i);        if ((chr & 0x80) != 0 && nBytes == 0){// 判断是否ASCII编码,如果不是,说明有可能是GBK            bAllAscii = false;        }        if (nBytes == 0) {            if (chr >= 0x80) {                if (chr >= 0x81 && chr <= 0xFE){                    nBytes = +2;                }                else{                    return false;                }                nBytes--;            }        }        else{            if (chr < 0x40 || chr>0xFE){                return false;            }            nBytes--;        }//else end    }    if (nBytes != 0)  {     //违反规则         return false;    }    if (bAllAscii){ //如果全部都是ASCII, 也是GBK        return true;    }    return true;}

使用boost库进行编码转换

boost大法好

#include <boost/locale.hpp>boost/locale/encoding.hpp中有这样的函数 template<typename CharType>std::string from_utf(CharType const *text,std::string const &charset,method_type how=default_method){    CharType const *text_end = text;    while(*text_end)         text_end++;    return from_utf(text,text_end,charset,how);}template<typename CharType>std::basic_string<CharType> to_utf(char const *text,std::string const &charset,method_type how=default_method){    char const *text_end = text;    while(*text_end)         text_end++;    return to_utf<CharType>(text,text_end,charset,how);}返回值是个stringutf转gbk可以std::string gbkstr =  boost::locale::conv::from_utf<char>(strUtf8.c_str(), "gb2312");//strUtf8是源utf8字符串同理gbk转utf8可以std::string utf8str = boost::locale::conv::to_utf<char>(strANSI.c_str(), "gb2312");//strANSI是源gbk字符串

linux utf8和gbk编码互转

utf8转gbk#include <iconv.h>char * UTF8toANSI(const std::string &from){    char *inbuf=const_cast<char*>(from.c_str());    size_t inlen = strlen(inbuf);    size_t outlen = inlen *4;    char *outbuf = (char *)malloc(inlen * 4 );    bzero( outbuf, inlen * 4);    char *in = inbuf;    char *out = outbuf;    iconv_t cd=iconv_open("GBK","UTF-8");    iconv(cd,&in,&inlen,&out,&outlen);    iconv_close(cd);    return outbuf;}

Windows utf8和gbk编码互转