初夏小谈：模拟memcpy，memmove

最新推荐文章于 2025-09-10 16:23:29 发布

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本文通过C语言代码详细展示了如何手动实现内存拷贝函数memcpy和memmove，memcpy用于当源和目标没有重叠时的高效拷贝，而memmove则能处理目标和源区域重叠的情况。代码中包含了完整的函数实现及示例调用。

menmcpy拷贝可以是字符型，自定义结构体等，不局限于字符串

#include<Aventador_SQ.h>

//模拟实现memcpy
void* Memcpy(void* dest, void* src, size_t count)
{
	void* ret = dest;
	while (count--)
	{
		*(char*)dest = *(char*)src;
		dest = (char*)dest + 1;
		src = (char*)src + 1;
	}
	return ret;
}

//模拟实现memmove
void* Memmove(void* dest, void* src, size_t count)
{
	void* ret = dest;
	if (dest <= src || (char*)dest >= (char*)src + count)
	{
		while (count--)
		{
			*(char*)dest = *(char*)src;
			dest = (char*)dest + 1;
			src = (char*)src + 1;
		}
	}
	else
	{
		dest = (char*)dest + count - 1;
		src = (char*)src + count - 1;
		while (count--)
		{
			*(char*)dest = *(char*)src;
			dest = (char*)dest + 1;
			src = (char*)src + 1;
		}
	}
	return ret;
}

int main()
{
	char arr[] = "2jin2gmin8gzhen";
	char arr1[1024] = "0";
	int x = strlen(arr);
	char* p=Memcpy(arr1, arr, x);
	printf("%s\n", p);
	printf("%s\n", arr);
	char* p1 = Memmove(arr1, arr, x);
	printf("%s\n", p1);
	printf("%s\n", arr1);
	system("pause");
	return 0;
}

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