파일 입출력 (binary)

#include<stdio.h>
#pragma warning (disable:4996)
typedef struct student
{
 char name[10];
 int age;

}STU;

void main()
{
 //2진(binary)입출력 함수

 FILE *fp;

 STU stu={"batman",30};
 STU buf;

 fp=fopen("c.txt","rb");   // b를 붙히면 binary란 뜻을 가진다.

 fprintf(fp,"%s %d\n",stu.name,stu.age);
 fwrite(&stu,sizeof(STU),1,fp);

 fread(&buf,sizeof(STU),1,fp);

 fclose(fp);

 printf("%s %d\n",buf.name,buf.age);     //콘솔창에 batman 30 출력

}

---

#include<stdio.h>
#include<stdlib.h>
#pragma warning(disable:4996);
struct a
{
 char name[10];
 int score[4];
 float avg;

};
void main()
{
 FILE*fp;
 struct a aa={"Jombie",1,2,3,6,2.f};

 fp=fopen("b.txt","wb");

 fwrite(&aa,sizeof(struct a),1,fp);

 fclose(fp);

}

​

---

 

#include<stdio.h>
#include<stdlib.h>
#pragma warning(disable:4996);
struct a
{
 char name[10];
 int score[4];
 float avg;

};
void main()
{
 FILE*fp;
 struct a aa={"Jombie",1,2,3,6,2.f};
 struct a bb;

 fp=fopen("b.txt","rb");

 fread(&bb,sizeof(struct a),1,fp);

 fclose(fp);
 printf("%s %d %d %d %d %f\n",bb.name,bb.score[0],bb.score[1],bb.score[2],bb.score[3],bb.avg);

}