The strcpy function copies strSource, including the terminating null character, to the location specified by strDestination. No overflow checking(这里) is performed when strings are copied or appended. The behavior of strcpy is undefined if the source and destination strings overlap.
The memcpy function copies count bytes of src to dest. If the source and destination overlap, this function does not ensure that the original source bytes in the overlapping region are copied before being overwritten. Use memmove to handle overlapping regions。