建立数据文件

[van_stephen]

做一个学籍成绩管理系统，如何从键盘输入数据，建立数据文件student.dat呢？

[wangdeqie]

//这么写
#include <stdio.h>
#define SIZE 4
struct student_type 
{
	char name[10];
	int num;
	int age;
}stud[SIZE];

void save()
{
	FILE* fp;
	int i;
	if ((fp=fopen("student.dat","wb"))==NULL)
	{
		printf("can not open ifle\n");
		return;
	}
	for (i=0;i<SIZE;i++)
	{
		if (fwrite(&stud[i],sizeof(struct student_type),1,fp)!=1)
		{
			printf("file write error\n");
		}
	}
	fclose(fp);
}

void main()
{	
	int i;
	for (i=0;i<SIZE;i++)
	{
		scanf("%s%d%d",stud[i].name,&stud[i].num,&stud[i].age);
	}
	save();
		  
}

[wangdeqie]

//看这个吧，完整的，先是写入到student.dat，再从student.dat读出！
#include <stdio.h>
#define SIZE 4
struct student_type 
{
    char name[10];
    int num;
    int age;
}stud[SIZE];

void save()
{
    FILE* fp;
    int i;
    if ((fp=fopen("student.dat","wb"))==NULL)
    {
        printf("can not open ifle\n");
        return;
    }
    for (i=0;i<SIZE;i++)
    {
        if (fwrite(&stud[i],sizeof(struct student_type),1,fp)!=1)
        {
            printf("file write error\n");
        }
    }
    fclose(fp);
}

void load()
{
	FILE* fp;
    int i;
    if ((fp=fopen("student.dat","rb"))==NULL)
    {
        printf("can not open ifle\n");
        return;
    }
    for (i=0;i<SIZE;i++)
    {
        fread(&stud[i],sizeof(struct student_type),1,fp);
		printf("%-10s %4d %4d\n",stud[i].name,stud[i].num,stud[i].age);
    }
    fclose(fp);
}
void main()
{    
    int i;
    for (i=0;i<SIZE;i++)
    {
        scanf("%s%d%d",stud[i].name,&stud[i].num,&stud[i].age);
    }
    save();
	load();


	
}
//Result under VC6:
li 9 9
zhang 3 4
wang 3 4
liu 4 4
li            9    9
zhang         3    4
wang          3    4
liu           4    4
Press any key to continue

[wangdeqie]

直接打开student.dat，看到的内容，会比较奇怪，因为文件里存的是二进制的！而输入的是ASC码，转换了一下！

[laiwusheng]

DAT files are data files, usually comma delimited, that contain data in ASCII format. These files are able to be open in a variety of programs including Microsoft Word and Microsoft Notepad.

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