实验7 文件应用编程

task1

#include<stdio.h>
#define N 7
#define M 80

typedef struct
{
    char name[M];  //书名
    char author[M];  //作者 
}BOOK;

int main()
{
    BOOK x[N] = {{"《雕塑家》","斯科特·麦克劳德"},
                {"《灯塔》","克里斯多夫·夏布特"},
                {"《五号屠杀场》","库尔特·冯内古特"},
                {"《出卖月亮的人》","罗伯特·海因莱茵"},
                {"《大地之上》","罗欣顿·米斯特里"},
                {"《上学记》","何兆武"},
                {"《命运》","蔡崇达"} };
                
    int i;
    FILE *fp;
    
    //以写的方式打开文本文件data1.txt
    fp=fopen("data1.txt","w");
    
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    //将结构体数组x中的图书信息写到fp指向的文件data1.txt
    //同时也输出到屏幕上
    for(i=0;i<N;++i)
    {
        fprintf(fp,"%-20s %-20s\n",x[i].name,x[i].author);
        printf("%-20s %-20s\n",x[i].name,x[i].author);
    }
    
    fclose(fp);
    
    return 0;
}

//从文本文件data1.txt中读取图书信息，并打印输出到屏幕
#include<stdio.h>
#define N 10
#define M 80

typedef struct
{
    char name[M];
    char author[M];
}BOOK;

int main()
{
    BOOK x[N];
    int i,n;
    FILE *fp;
    
    fp = fopen("data1.txt","r");
    
    if(fp == NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    i=0;
    while(!feof(fp))
    {
        fscanf(fp,"%s%s",x[i].name,x[i].author);
        ++i;
    }
    n = i;
    
    //将图书信息打印输出到屏幕上
    for(i=0;i<n;++i)
    printf("%d. %-20s%-20s\n",i+1,x[i].name,x[i].author);
    
    fclose(fp);
    
    return 0; 
}

 

 

 

task2

//将图书信息写入二进制文件data2.dat

#include<stdio.h>
#define N 7
#define M 80

typedef struct
{
    char name[M];
    char author[M];
}BOOK;

int main()
{
    BOOK x[N] = {{"《雕塑家》","斯科特·麦克劳德"},
                {"《灯塔》","克里斯多夫·夏布特"},
                {"《五号屠杀场》","库尔特·冯内古特"},
                {"《出卖月亮的人》","罗伯特·海因莱茵"},
                {"《大地之上》","罗欣顿·米斯特里"},
                {"《上学记》","何兆武"},
                {"《命运》","蔡崇达"} };
    int i;
    
    FILE *fp;
    
    fp = fopen("data2.dat","wb");
    
    //如果打开文件失败，输出提示信息并返回 
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    //将结构体数组x中的图书信息以数据块方式写入文件data2.dat 
    fwrite(x,sizeof(BOOK),N,fp);
    
    fclose(fp);
    return 0;
 } 

//从二进制文件data2.dat读取图示信息，并打印输出到屏幕
#include<stdio.h>
#define N 7
#define M 80

typedef struct 
{
    char name[M];
    char author[M];
}BOOK;

int main()
{
    BOOK x[N];
    int i;
    
    FILE *fp;
    
    //以读的方式打开二进制文件data2.dat
    fp = fopen("data2.dat","rb");
    
    if(fp ==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    //从文件data2.dat以数据块方式读入图书信息数据结构体数组x
    fread(x,sizeof(BOOK),N,fp);
    
    //在屏幕上输出结构体数组x中存储的图书信息
    for(i=0;i<N;i++)
    printf("%d.%-20s%-20s\n",i+1,x[i].name,x[i].author);
    
    fclose(fp);
    return 0; 
}

 

 

 

task3

//使用fputs()将字符串写入文本文件

#include<stdio.h>
#define N 5
#define M 80

int main()
{
    char songs[N][M]={"Working\'s Blues",
                      "Everything Will Flow",
                      "Streets of London",
                      "Perfect Day",
                      "Philadelphia"};
    int i;
    FILE *fp;
    
    fp = fopen("data3.txt","w");
    
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    for(i=0;i<N;++i)
    {
        fputs(songs[i],fp);
        fputs("\n",fp);
    }
    
    fclose(fp);
    return 0;
}

//使用fgets()从文件中读取字符串并在屏幕上显示

#include<stdio.h>
#define N 5
#define M 80

int main()
{
    char songs[N][M];
    int i;
    FILE *fp;
    
    fp = fopen("data3.txt","r");
    
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    for(i=0;i<N;++i)
    fgets(songs[i],80,fp);
    
    for(i=0;i<N;++i)
    printf("%d. %s",i+1,songs[i]);
    
    fclose(fp);
    return 0;
}

#include<stdio.h>
int main()
{
    char ch;
    FILE *fp;
    
    fp = fopen("data3.txt","r");
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    ch = fgetc(fp);
    while(ch!=EOF)
    {
        putchar(ch);
        ch = fgetc(fp);
    }
    
    fclose(fp);
    return 0;
}

 

 

 

task4

#include<stdio.h>

typedef struct
{
    char sen[30];
}SENTENCE;
int main()
{
    SENTENCE x[2] = {{"nuist2022 - nuist2023"},{"FIFA World Cup 2022"}};
    int i,sum=0;
    char *p,*q;
    FILE *fp;
    
    fp = fopen("data4.txt","w");
    
    if(fp==NULL)
    {
        printf("fail to open file\n");
        return 1;
    }
    
    for(i=0;i<2;i++)
    {
        fprintf(fp,"%s\n",x[i].sen);
    }
    
    p = &x[0].sen;
    while(*p!='\0')
    {
        if(*p == ' ')
        {
            p++;
            continue;
        }
        sum++;
        p++;
    }
    
    q = &x[1].sen;
    while(*q!='\0')
    {
        if(*q ==' ')
        {
            q++;
            continue;
        }
        sum++;
        q++;
    }
    
    printf("data4.txt中共包含字符数(不计空白符): %d\n",sum);
    
    fclose(fp);
    return 0;
}

 

 

 

task5

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define N 10

typedef struct
{
    long int id;
    char name[20];
    float objective;  //客观题得分
    float subjective;  //操作题得分
    float sum;
    char level[10]; 
}STU;

void input(STU s[],int n);
void output(STU s[],int n);
void process(STU s[],int n);
int main()
{
    STU stu[N];
    
    printf("从文件读入%d个考生信息：准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n",N);
    input(stu,N);
    
    printf("\n对考生信息进行处理：计算总分，确定等级\n");
    process(stu,N);
    
    printf("\n打印考生完整信息，并保存到文件中");
    output(stu,N);
    
    return 0;
}

void input(STU s[],int n)
{
    int i;
    FILE *fin;
    
    fin = fopen("examinee.txt","r");
    if(fin == NULL)
    {
        printf("fail to open file\n");
        exit(0);
    }
    
    while(!feof(fin))
    {
        for(i=0;i<n;i++)
        fscanf(fin,"%ld %s %f %f",&s[i].id,s[i].name,&s[i].objective,&s[i].subjective);
    }
    fclose(fin);
}
//输出考生完整信息，并写到文本文件result.txt中
void output(STU s[],int n)
{
    FILE *fout;
    int i;
    
    printf("\n");
    printf("准考证号\t姓名\t客观题得分\t操作题得分\t总分\t\t等级\n");
    for(i=0;i<n;i++)
        printf("%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n",s[i].id,s[i].name,s[i].objective,s[i].subjective,s[i].sum,s[i].level);
    //保存到文件 
    fout = fopen("result.txt","w");
    
    if(!fout)
        {
            printf("fail to open or create result.txt\n");
            exit(0);
        }
        
    fprintf(fout,"准考证号\t\t姓名\t客观题得分\t操作题得分\t总分\t\t等级\n");
        
    for(i=0;i<n;i++)
        fprintf(fout,"%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n",s[i].id,s[i].name,s[i].objective,s[i].subjective,s[i].sum,s[i].level);
            
    fclose(fout);
}

void process(STU s[],int n)
{
    int i,j;
    STU t;
    for(i=0;i<n;i++)
    {
        s[i].sum = s[i].objective + s[i].subjective;
    }
    for(i=0;i<n;i++)
    {
        for(j=0;j<n-1-i;j++)
        {
        if(s[j+1].sum>s[j].sum)
        {
            t = s[j];
            s[j] = s[j+1];
            s[j+1] = t;
        }
        }
    }
    for(i=0;i<n;i++)
    {
        if(i<n*0.1)
            strcpy(s[i].level,"优秀");
        else if(i>=n*0.1&&i<n*0.5)
            strcpy(s[i].level,"合格");
        else
            strcpy(s[i].level,"不合格"); 
    }
}

 

 

 

task6

#include <stdio.h>
#include <time.h>
#define N 20
#define M 80
typedef struct
{
    char no[N];
    char name[N];
    char classname[N];
}STU;
int main()
{
    int i=0,flag[M]={0},k;
    STU a[M],b[5];
    FILE *fp,*ptr;
    
    fp=fopen("list.txt","r");
    ptr=fopen("lucky.txt","w");
    
    if(fp==NULL)
    {
        printf("fail to open\n");
        return 1;
    }
    
    if(ptr==NULL)
    {
        printf("fail to open\n");
        return 1;
    }
    
    while(!feof(fp))
    {
        fscanf(fp,"%s%s%s",a[i].no,a[i].name,a[i].classname);
        i++;
    }
    srand((unsigned)time(NULL));
    for(i=0;i<5;)
    {
        k=rand()%80;
        if(flag[k]==0)
            b[i++]=a[k];
        flag[k]=1;
        
        
    }
    for(i=0;i<5;i++)
    {
        printf("%-20s%-20s%-20s\n",b[i].no,b[i].name,b[i].classname);
        fprintf(ptr,"%-20s%-20s%-20s\n",b[i].no,b[i].name,b[i].classname);
    }
    fclose(fp);
    fclose(ptr);
    return 0;
}