harage[4];/*年龄*/?charmajor[20];/*专业*/?charclasss[8];/*班级*/}st[N],t;sort_message()/*排序模块*/{inti,j,fno,fsize,fnum;?FILE*fp;?fp=fopen("student.txt","rt+");if(fp==NULL){printf("\n\n*****文件打开错误。按任意键退出!");getchar();exit(1);}fno=fileno(fp);fsize=filelength(fno);fnum=fsize/sizeof(structst_message);for(i=0;i<fnum;i++)?fread(&st[i],sizeof(structst_message),1,fp);for(i=0;i<fnum-1;i++)?for(j=i+1;j<fnum;j++)?if(strcmp(st[i].num,st[j].num)>0)?{t=st[i];?st[i]=st[j];?st[j]=t;?}rewind(fp);for(i=0;i<fnum;i++)?fwrite(&st[i],sizeof(structst_message),1,fp);fclose(fp);}input_message()/*录用信息模块*/{inti;charchoice;FILE*fp;fp=fopen("student.txt","at+");if(fp==NULL){printf("\n\n*****库存文件不存在!请建立。按任意键退出!");getchar();exit(1);}for(i=0;;i++){system("cls");getchar();printf("请输入学生姓名:");gets(st[i].name);printf("\n请输入学生班级:");