#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
char name[M];
char author[M];
}Book;
int main()
{
Book x[N]={{"一九四八","乔治.奥威尔"},
{"美丽新世界","赫胥黎"},
{"昨日的世界","斯蒂芬.茨威格"},
{"万历十五年","黄仁宇"},
{"一只特立独行的猪","王小波"}
};
int i;
FILE *fp;
fp=fopen("datal.txt","w");
if(fp==NULL)
{
printf("fail to open file\n");
return 1;
}
for(i=1;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;
}
![]()
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
char name[M];
char author[M];
}Book;
int main()
{
Book x[N];
int i;
FILE *fp;
fp=fopen("data1.txt","r");
if(fp==NULL)
{
printf("fail to open file\n");
return 1;
}
for(i=0;i<N;++i)
{
fscanf(fp,"%s %s\n",x[i].name,x[i].author);
printf("%-20s %-20s\n",x[i].name,x[i].author);
}
fclose(fp);
return 0;
}
![]()
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
char name[M]; // 书名
char author[M]; // 作者
}Book;
int main()
{
Book x[N] = { {"一九八四", "乔治.奥威尔"},
{"美丽新世界", "赫胥黎"},
{"昨日的世界", "斯蒂芬.茨威格"},
{"万历十五年", "黄仁宇"},
{"一只特立独行的猪", "王小波"}
};
int i;
FILE *fp;
// 以写的方式打开二进制文件data2.dat
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中的图书信息写以数据块方式写入文件
// 把从地址x处开始sizeof(Book)×N个字节大小的数据块写入fp指向的文件
fwrite(x, sizeof(Book), N, fp);
fclose(fp);
}
#include <stdio.h>
#define N 5
#define M 80
typedef struct
{
char name[M]; // 书名
char author[M]; // 作者
}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");
// 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;
}
// 从fp指向的文件中读取数据块到x对应的地址单元
// 数据块大小为sizeof(Book)×N
fread(x, sizeof(Book), N, fp);
// 在屏幕上输出结构体数组x中保存的数据
for(i=0; i<N; ++i)
printf("%-20s%-20s\n", x[i].name, x[i].author);
fclose(fp);
return 0;
}
![]()
#include <stdio.h>
int main()
{
FILE *fin,*fout;
char ch;
fin=fopen("data3_1.txt","r");
if(fin==NULL)
{
printf("fail to open data3_1.txt\n");
return 1;
}
fout=fopen("data3_2.txt","w");
if(fout==NULL)
{
printf("fail to open data3_2.txt\n");
return 1;
}
while(!feof(fin))
{
ch=fgetc(fin);
if(ch>='a'&&ch<='z')
ch-=32;
fputc(ch,fout);
}
fclose(fin);
fclose(fout);
return 0;
}
![]()
#include <stdio.h>
int main()
{
FILE *fin;
char ch;
int count=0;
if((fin=fopen("data3_1.txt","r"))==NULL)
{
printf("fail to open data3_1.txt");
return 1;
}
while(!feof(fin))
{
ch=fgetc(fin);
if(ch!=' '&&ch!='\n'&&ch!='\t'&&ch!=EOF)
{
count++;
}
}
printf("data3_1.txt中共包含字符数=%d",count);
fclose(fin);
return 0;
}
![]()
#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);
}
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);
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(j=0;j<n-1;j++)
for(i=0;i<n-j-1;i++)
{
if(s[i].sum<s[i+1].sum)
{
t=s[i];
s[i]=s[i+1];
s[i+1]=t;
}
}
for(i=0;i<1;i++)
{
strcpy(s[i].level,"优秀");
}
for(;i>=i&&i<5;i++)
strcpy(s[i].level,"合格");
for(;i<n;i++)
{
strcpy(s[i].level,"不合格");
}
}
![]()
#include <stdio.h>
#include <stdlib.h>
#include<time.h>
#define N 80
#define M 5
typedef struct
{
long int id;
char name[20];
char lass[80];
}STU;
int main()
{
int i,j;
STU x[N],y[M];
FILE *fin,*fout;
fin=fopen("list.txt","r");
if(fin==NULL)
{
printf("fail to open list.txt\n");
return 1;
}
for(i=0;i<N;i++)
{
fscanf(fin,"%ld %s %s",&x[i].id,x[i].name,x[i].lass);
}
fclose(fin);
srand(time(0));
j=rand()%(80)+i;
for(i=0;i<M;i++)
y[i]=x[j];
j=rand()%(80)+1;
fout=fopen("lucky.txt","w");
if(fout==NULL)
{
printf("fail to open list.txt\n");
return 1;
}
for(i=0;i<M;i++)
{
fprintf(fout,"%ld %s %s\n",&x[i].id,x[i].name,x[i].lass);
printf("%ld %s %s\n",&x[i].id,x[i].name,x[i].lass);
}
fclose(fout);
return 0;
}
![]()