C语言关于文件写入，蹲个代码

第六题

#include <stdio.h>
#include <string.h>
int main()
{
    int n,len;
    char buf[100]={0};
    FILE* fp = fopen("test.txt","w");
    if(fp == NULL)
    {
        printf("file open error");
        return 0;
    }
    printf("input the number of lines to be written:");
    scanf("%d",&n);
    getchar();
    while(n)
    {
        gets(buf);
        len = strlen(buf);
        buf[len] = '\n';
        len++;
        buf[len] = 0;
        fwrite(buf,1,strlen(buf),fp);
        n--;
    }
    fclose(fp);
    return 0;
}