strncat函数模拟实现

strncat函数在cplusplus网站中的定义

模拟实现源码

//strncat函数模拟实现
#include <stdio.h>
#include <string.h>
#include <assert.h>

char* my_strncat(char* destination, const char* source, size_t num)
{
	assert(destination && source);
	char* ret = destination;

	while (*destination)
	{
		destination++;
	}

	while (num--)
	{
		*destination = *source;
		destination++;
		source++;
	}

	return ret;
}

int main()
{
	char arr1[] = "efgh";
	char arr2[20] = "abcd";

	printf("arr2:%s\n", arr2);

	char* ret = my_strncat(arr2, arr1, 3);

	printf("arr1:%s\n", arr1);
	printf("arr2:%s\n", arr2);

	
	return 0;
}

执行结果