//11．利用文本编辑软件在外存上建立一个有n个学生的学号、姓名、系别、联系电话的数据文件。从键盘上输入一个学号，可以查寻到此人其他信息。
//并按姓名排序且输出。
#include<stdio.h>
#include<stdlib.h>
#define SIZE 6
struct stu
{
    int idnumber;
    char name;
    char major;
    char *telnumber;
};
main()
{
    struct stu S[SIZE];
    int i,ID;
    FILE *fp;
    fp=fopen("file1.txt","r");
    if(fp==NULL)
    {
        printf("\n Error!Open the file fail!\n");
        exit(1);
    }
    printf("\n idnumber name  major  telnumber  \n");
   
    for(i=0;fread((&S[i]),sizeof(struct stu),1,fp)!=0;i++)
        printf("%10d%6s%6s%11s\n",S[i].idnumber,S[i].name,S[i].major,S[i].telnumber);
   
    printf("\nNow you can input one student's idnumber :\n");
    scanf("%d",&ID);
    for(i=0;fread((S+i),sizeof(struct stu),1,fp)!=0;i++)
        if(ID==S[i].idnumber)
            printf("idnumber:%d\nname:%s\nmajor:%s\ntelnumber:%s\n",S[i].idnumber,S[i].name,S[i].major,S[i].telnumber);
    fclose(fp);
}
这个程序编译和链接都没有问题就是不能运行，那位给看看呗……

#include<stdio.h>
#include<stdlib.h>
#define SIZE 6
struct stu
{
    int idnumber;
    char name;
    char major;
    char *telnumber;
};
main()
{
    struct stu S[SIZE];
    int i,ID;
    FILE *fp;
    fp=fopen("file1.txt","w+");        //只错在这一个地方，若是文件不存在，你用“r”,它就会提示你出错，“w+”，在文件不存在的时候会自动创建新文件，
                                         //仔细看一下文件mode的作用吧     
    if(fp==NULL)
    {
        printf("\n Error!Open the file fail!\n");
        exit(1);
    }
    printf("\n idnumber name  major  telnumber  \n");
     
    for(i=0;fread((&S[i]),sizeof(struct stu),1,fp)!=0;i++)
        printf("%10d%6s%6s%11s\n",S[i].idnumber,S[i].name,S[i].major,S[i].telnumber);
     
    printf("\nNow you can input one student's idnumber :\n");
    scanf("%d",&ID);
    for(i=0;fread((S+i),sizeof(struct stu),1,fp)!=0;i++)
        if(ID==S[i].idnumber)
            printf("idnumber:%d\nname:%s\nmajor:%s\ntelnumber:%s\n",S[i].idnumber,S[i].name,S[i].major,S[i].telnumber);
    fclose(fp);
}