| ptr1 | Pointer to the first memory buffer. |
| ptr2 | Pointer to the second memory buffer to compare the first one to. |
| size | Number of bytes to compare. |
void 0 if the contents are identical, non-zero otherwise.
Checks to see whether two memory regions are identical or not by comparing a specified memory region in the first given memory buffer with the same region in the second given memory buffer.
The memory regions may overlap. Returns 0 if the contents of the two regions are identical.