C语言实现字节流与十六进制字符串的相互转换

//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 ;

}