my_memmove,my_strcpy

#include <stdio.h>
void *my_memmove(void *dest, const void *src, size_t count)
{
	void *ret = dest;
	char *c_dest = (char*)dest;
	char *c_src = (char*)src;

	if((dest == NULL) || (src == NULL)) {
		return NULL;
	}
	
	if(c_dest <= c_src) {
		while(count--) {
			*c_dest++ = *c_src++;
		}
	} else {
		c_dest += count - 1;
		c_src += count - 1;
		while(count--) {
			*c_dest-- = *c_src--;
		}
	}

	return ret;
}

int main(void)
{
	char a[] = "abcdefgh";
	printf("%s\n", a);
	printf("%s\n", my_memmove(&a[2], a, 3));
	printf("%s\n", a);
	return 0;
}

#include <stdio.h>
char * strcpy(char *dst,const char *src)
{
	char *ret = dst;

	if((dst == NULL) || (src == NULL)) {
		return NULL;	
	}

	while ((*dst++ = *src++) != '\0'); 

	return ret;
}

int main(void)
{
	char a[10] = {0};

	printf("%s\n", strcpy(a, "abcd"));
	return 0;
}