_memccpy函数（memccpy）

最新推荐文章于 2022-07-21 02:21:36 发布

原创最新推荐文章于 2022-07-21 02:21:36 发布 · 1k 阅读

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该博客介绍了_cmemccpy函数的用法，包括参数解析和返回值说明。函数用于复制内存区域，直到遇到特定字符为止。当找到该字符时，返回目标内存区域中该字符之后的指针。如果未找到指定字符，则返回NULL。

_memccpy
void *_memccpy(
void *dest,
const void *src,
int c,
size_t count
);

Parameters
dest
Pointer to the destination.

src
Pointer to the source.

c
Last character to copy.

count
Number of characters.

Return Value
If the character c is copied, _memccpy returns a pointer to the char in dest that immediately follows the character. If c is not copied, it returns NULL.


```cpp
#include <memory.h>
#include <stdio.h>
#include <string.h>
#include<iostream>

using namespace std;

int main(void)
{
	//char buffer[41] = { '0' };

	char string1[20] = "The qkhh";
	***char buffer[5] = { '0' };***
	char *pdest;

	printf("Function: _memccpy 60 characters or to character ' '\n");
	printf("Source: %s\n", string1);
	pdest = (char *)_memccpy(buffer, string1, 'e', 20);
	cout << pdest << endl;
	//*pdest = '\0';
	printf("Result: %s\n", buffer);
	printf("Length: %d characters\n", strlen(buffer));

	system("pause");
	return 0;
}

输出
![在这里插入图片描述](https://img-blog.csdnimg.cn/20200205005909479.png)

```cpp
#include <memory.h>
#include <stdio.h>
#include <string.h>
#include<iostream>

using namespace std;

int main(void)
{
	//char buffer[41] = { '0' };

	char string1[20] = "The qkhh";
	***char buffer[5];***
	char *pdest;

	printf("Function: _memccpy 60 characters or to character ' '\n");
	printf("Source: %s\n", string1);
	pdest = (char *)_memccpy(buffer, string1, 'e', 20);
	cout << pdest << endl;
	//*pdest = '\0'; 此位置可达到与上面相同输出效果
	printf("Result: %s\n", buffer);
	printf("Length: %d characters\n", strlen(buffer));

	system("pause");
	return 0;
}

输出
在这里插入图片描述
_memccpy函数若函数在指定空间大小之内遇到指定字符则返回值目标函数的指针，需要将返回值置为‘\0’，否则编译器自动填充，出现错误。