C语言实现按位拷贝

在程序开发过程中，我们经常会用到按位拷贝一串二进制数，在此提供一个按位拷贝的函数给大家参考，函数源码如下：

 #define char_t   char
 #define uint8_t  unsigned char
 #define int8_t   signed char
 #define uint16_t unsigned short
 #define int16_t  signed short
 #define uint32_t unsigned  long int
 #define int32_t  signed long int  

 /*
  * param[in]  SrcData: source data
  * param[in]  StartsrcBit: start source bit(1, 2, 3, ...)
  * param[in]  startdstbit: start destination bit(1, 2, 3, ...)
  * param[in]  CopyLen: copy length
  * param[out] DstData: destination data
 */
 void copy_data_by_bits(uint8_t *DstData, uint32_t startdstbit, uint8_t *SrcData,  uint32_t StartsrcBit, uint32_t CopyLen)
 {
     uint32_t copysrcbyte        = ;
     uint32_t copysrcbitofbyte   = ;
     uint32_t copydstbyte        = ;
     uint32_t copydstbitofbyte   = ;
     uint32_t dataLen            = CopyLen;  

     if ((NULL == SrcData) || (NULL == DstData)) {
         printf("SrcData or DstData is NULL !!!\n");
         return;
     }  

     while (dataLen > )  {
         copydstbyte       = ((startdstbit + dataLen) / );
         copydstbitofbyte  = ((startdstbit + dataLen) % );
         copysrcbyte       = ((StartsrcBit + dataLen) / );
         copysrcbitofbyte  = ((StartsrcBit + dataLen) % );  

         if ( == copysrcbitofbyte) {
             copysrcbitofbyte = ;
             copysrcbyte      = copysrcbyte - ;
         }  

         if ( == copydstbitofbyte) {
             copydstbitofbyte = ;
             copydstbyte      = copydstbyte - ;
         }  

         DstData[copydstbyte]  &= ~( << (copydstbitofbyte - ));
         if ((SrcData[copysrcbyte] & ((uint8_t)((uint8_t) << (copysrcbitofbyte - )))) != ) {
             DstData[copydstbyte] |= ((uint8_t) << (copydstbitofbyte - ));
         }
         dataLen--;
     }
 }  

测试代码：

 int main(void)
 {
     uint8_t SrcData[] = {0x12, 0x34, 0x56, 0x78};
     uint32_t StartsrcBit = ;
     uint32_t CopyLen = ;
     uint8_t DstData[] = {};
     uint32_t startdstbit = ;  

     DstData[] = 0xab;
     copy_data_by_bits(DstData, startdstbit, SrcData, StartsrcBit, CopyLen);
     printf("DstData[0]:%#04x  DstData[1]:%#04x\n", DstData[], DstData[]);  

     return ;
 }  

分析如下：