内存操作算法

memcpy（）

void *memcpy(void *dest, const void *src, size_t count)
{
assert(dest != NULL && src != NULL);
char *tmp = dest;
const char *s = src;
while (count--)
*tmp++ = *s++ ;
return dest;
}

memmove（）

#include <linux/string.h>
#undef memmove
void  *memmove ( void  * dest, const   void  *src, size_t  count)
{
assert(dest == NULL || str == NULL || count <= 0);

if  (dest < src) {
__inline_memcpy(dest,src,count);
}  else  {
char  *p = ( char  *) dest + count;
char  *s = ( char  *) src + count;
while  (count--)
*--p = *--s;
}
return  dest;
}