C语言实现字节流与十六进制字符串的相互转换

- 日理万妓 2022-12-28 14:22 210阅读 0赞

//字节流转换为十六进制字符串
    void ByteToHexStr(const unsigned char* source, char* dest, int sourceLen)
    {
        short i;
        unsigned char highByte, lowByte;
     
        for (i = 0; i < sourceLen; i++)
        {
            highByte = source[i] >> 4;
            lowByte = source[i] & 0x0f ;
     
            highByte += 0x30;
     
            if (highByte > 0x39)
                    dest[i * 2] = highByte + 0x07;
            else
                    dest[i * 2] = highByte;
     
            lowByte += 0x30;
            if (lowByte > 0x39)
                dest[i * 2 + 1] = lowByte + 0x07;
            else
                dest[i * 2 + 1] = lowByte;
        }
        return ;
    }
     
    //字节流转换为十六进制字符串的另一种实现方式
    void Hex2Str( const char *sSrc,  char *sDest, int nSrcLen )
    {
        int  i;
        char szTmp[3];
     
        for( i = 0; i < nSrcLen; i++ )
        {
            sprintf( szTmp, "%02X", (unsigned char) sSrc[i] );
            memcpy( &sDest[i * 2], szTmp, 2 );
        }
        return ;
    }
     
    //十六进制字符串转换为字节流
    void HexStrToByte(const char* source, unsigned char* dest, int sourceLen)
    {
        short i;
        unsigned char highByte, lowByte;
        
        for (i = 0; i < sourceLen; i += 2)
        {
            highByte = toupper(source[i]);
            lowByte  = toupper(source[i + 1]);
     
            if (highByte > 0x39)
                highByte -= 0x37;
            else
                highByte -= 0x30;
     
            if (lowByte > 0x39)
                lowByte -= 0x37;
            else
                lowByte -= 0x30;
     
            dest[i / 2] = (highByte << 4) | lowByte;
        }
        return ;
    }