/*munum.c按用戶序號修改用戶信息*/
#include "stdio.h"
void ModifyByUserNumber()
 {
    int i,j,k;
    long modnum;
    /*輸入各項修改后信息*/
    long Number;
    char Name[20];
    char ps[8];
    int power;
    user TmpS;
    user s[SIZE];/*SIZE，在user.h頭文件中定義的常量，值為100  */
    int recNumber;
    char DataFile[40] = "yonghu",next;
    FILE *fp;/*====fp指針指向存儲數據的文件名====*/
begin:
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file %s fail!End with any key\n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("please input the user'seatnum which you will modify:");
    scanf("%ld",&modnum);
    printf("the user you will delete is:%ld\n",modnum);
    /*輸入要修改紀錄的信息*/
    Number=modnum;
    printf("name=");
    scanf("%s",Name);

    printf("ps=");
    scanf("%s",ps);

    printf("power=");
    scanf("%d",&power);


   /*將文件中要修改的信息存入結構體數組*/
   recNumber=0;
    while((fread(&TmpS,sizeof(user),1,fp)) != (int)NULL)
    {
        if(TmpS.Number!=modnum)
            {
            s[recNumber].Number = TmpS.Number;
            strcpy(s[recNumber].Name, TmpS.Name);
            strcpy(s[recNumber].ps,TmpS.ps);
            s[recNumber].power = TmpS.power;
            recNumber++;
            }
        else
            {
            s[recNumber].Number = Number;
            strcpy(s[recNumber].Name, Name);
            strcpy(s[recNumber].ps,ps);
            s[recNumber].power = power;
            recNumber++;
            }

    }
    printf("\nrecNumber%d\n",recNumber);
    fclose(fp);
    /*====將刪除后的結構體記錄寫入文件====*/
        fp=fopen(DataFile,"wb+");
        if (fp == NULL)
        {
            printf("\nSet up file %sfail !end with anykey.\n",DataFile);
            perror("Set up fail");
            getch();
            exit(1);
        }
        for(i=0; i<recNumber; i++)
        {
            if(fwrite(&s[i],sizeof(user),1,fp)!=1)
            {
                printf("\nWrite file %s fail!end with anykey.\n",DataFile);
                perror("Write file fail!");
                    getch();
                    exit(1);
            }
        }
        fclose(fp);
    fp=fopen(DataFile,"rb");
    if (fp == NULL)
    {
        printf("\nOpen file%sfail!End with any key \n",DataFile);
        perror("Open file fail");
        getch();
        exit(1);
    }
    printf("the file after modify is:\n");
    printf("\nNumber \t\tName\tps\tpower\n");
    while(fread(&TmpS,sizeof(user),1,fp) != (int)NULL)
    {
        if(TmpS.Number!=0)
        printf("\n%ld\t        %s\t   %s\t  %d\n",TmpS.Number,TmpS.Name,TmpS.ps,TmpS.power);
    }
    fclose(fp);

    printf("\nGo on ?(y/n)");
    next=getche();
    putchar('\n');
    if ( next =='y' || next =='Y') goto begin;
 }