要求：

1.使用fgetsline number of the statistics file

2.使用fgets/fputs拷贝文件

思路：
1.在./a.outThen enter a file to count the line number of the file
2.在./a.outThen enter two files to copy the first file and copy it to the second file.Create a second file and make a copy when the second file does not exist.
源代码如下：
main.c

#include <head.h>
#include "homework.h"

int main(int argc, const char *argv[])
{
    
    FILE *fp, *fp1;
    int a = argc;
    if (a == 2)
    {
    
        if ((fp = fopen(argv[1], "r")) == NULL)
        PRINT_ERR("打开文件失败");
        line_file(a, fp);
    }
    else if (a == 3)
    {
    
        if ((fp = fopen(argv[1], "r")) == NULL)
        PRINT_ERR("打开文件失败");
        if ((fp1 = fopen(argv[2], "a")) == NULL)
        PRINT_ERR("打开文件失败");
        copy_file(a, fp, fp1);
    }

    return 0;
}

head.h

#ifndef __HEAD_H__
#define __HEAD_H__

#include <stdio.h>
#include <errno.h>
#include <string.h>

#define PRINT_ERR(msg) \ do{
       \ perror(msg); \ return -1; \ }while(0)

        
#endif

work.c

#include <head.h>


int copy_file(int a, FILE *fp, FILE *fp1)
{
    
    char buffer[10];
    if (a != 3)
    {
    
        printf("input error,try again\n");
        printf("usage:./a.out filename filename\n");
        return -1;
    }

    while ((fgets(buffer, sizeof(buffer), fp)) != NULL)
    {
    
        fputs(buffer, fp1);
    }
    fclose(fp);
    fclose(fp1);
    return 0;
}

int line_file(int a, FILE *fp)
{
    

    int num = 0;
    char buffer[10];
    if (a != 2)
    {
    
        printf("input error,try again\n");
        printf("usage:./a.out filename\n");
        return -1;
    }
    while ((fgets(buffer, sizeof(buffer), fp)) != NULL)
    {
    
        if (buffer[strlen(buffer) - 1] == '\n')
        {
    
            num++;
        }
    }
    printf("该文件有%d行\n", num);
    fclose(fp);
    return 0;
}

work.h

#ifndef __HOMEWORK_H__
#define __HOMEWORK_H__

int copy_file(int a, FILE *fp, FILE *fp1);
int line_file(int a, FILE *fp);

#endif