lendinf.c

是一个比较好的图书管理系统

/**********************************************/
/*         LendInf.c                          */
/**********************************************/

#include <stdio.h>
#include <string.h>
#include <dos.h>
#include "ReaderMS.c"

#define ONCEMAX 3   /* 每人借阅的最大数目 */
#define BKIDSZ 6
#define TIMESZ 9

struct LendInfor
{
   char rdID[RDIDSZ];
   char bkCount;
   char bkID[ONCEMAX][BKIDSZ];
   char StartTime[ONCEMAX][TIMESZ];
   char EndTime[ONCEMAX][TIMESZ];
};


static const int LDRECSIZE = sizeof(struct LendInfor);
struct LendInfor *cur_lend_ptr;


/******************************************/
/*        funtions declarations           */
void Lend_File_Init();
void Add_Lend_Record(int);
void Load_Lend_Record(int recordNum);
void Save_cur_Lend_Node();
int Overdue_Judge(char *p);



/**************************************************************/
/*    Initailize the book datafile, if the file is not exsit, */
/* to create a new file. If it is exsit and is a new file,    */
/* the InforWord is not exsit, to write the new InforWord to  */
/* the head of the file                                       */

void Lend_File_Init()
{
     char ch;
     printf("Lend File Initializing...\n");
     delay(3000);
     if(fopen("LendData.txt","r")==NULL)
     {
         printf("Open File Error!\n");
         printf("Press any key to create a new file!");
         getch();
         printf("\n");

         /*the file is not exist, create the file   */
         if(fopen("LendData.txt","w+")==NULL)
         {
             printf("Create File Error!\n");
             return;
         }
         printf("Create file successful!\n");
         printf("The file is LendData.txt!\n");
     }
     return;
}

/******************************/
/* add a new lend record      */

void Add_Lend_Record(int p)
{
    int i, num;
    char newID[RDIDSZ];
    struct LendInfor *new_lend_node;
    new_lend_node = 
           (struct LendInfor *)malloc(LDRECSIZE);
    if(new_lend_node==NULL)
    {
        printf("Memory Error!\n");
        return;
    }

    num = p;
    for(i=RDIDSZ-2; i>=0; i--)
    {
         newID[i] = num%10 + 48;
         num = num/10;
    }
    newID[RDIDSZ-1] = '\0';
    strcpy(new_lend_node->rdID, newID);

    new_lend_node->bkCount = '0';

    for(i=0; i<ONCEMAX; i++)
    {
        strcpy(new_lend_node->bkID[i], "*****");
        strcpy(new_lend_node->StartTime[i], "********");
        strcpy(new_lend_node->EndTime[i], "********");
    }
    cur_lend_ptr = new_lend_node;
    new_lend_node = NULL;

    Save_cur_Lend_Node();

    free(cur_lend_ptr);
    cur_lend_ptr = NULL;
    return;
}


/********************************************************************/
/* to load a record from the file to the pointer(cur_reader_ptr)    */

void Load_Lend_Record(int recordNum)
{
    int i;
    int step = 0, loop;
    char ch;
    FILE *rfp;
    struct LendInfor *new_Node_ptr;
    new_Node_ptr =
         (struct LendInfor *)malloc(LDRECSIZE);

    if((rfp=fopen("LendData.txt","r")) == NULL)
    {
     printf("Open File Error!\n");
     return;
    }

    step = recordNum * LDRECSIZE;
    fseek(rfp, step, 0);
    fread(new_Node_ptr, LDRECSIZE, 1, rfp);

    cur_lend_ptr = new_Node_ptr;
    new_Node_ptr = NULL;
    fclose(rfp);
    return;
}


/************************************/
/*  to save the current lend record */

void Save_cur_Lend_Node()
{
    int num, step;
    FILE *wfp;
    num = atoi(cur_lend_ptr->rdID);
    
    /*找到记录插入位置  */
    step = num * LDRECSIZE;
    if((wfp=fopen("LendData.txt","r+")) == NULL)
    {
     printf("Open File Error!\n");
     return;
    }
    fseek(wfp, step, 0);
    fwrite(cur_lend_ptr, LDRECSIZE, 1, wfp);  /*用数据块写入方式 */

    fclose(wfp);   /*关闭文件*/
    return;
}


/*********************************************/
/*   to judge the lending is overdue or not  */

int Overdue_Judge(char *p)
{
    long cur_time, p_time;
    char instr[TIMESZ], mon_str[3], day_str[3];
    struct date *cur_date;
    cur_date = (struct date *)malloc(sizeof(struct date));

    getdate(cur_date);
    sprintf(instr, "%d", cur_date->da_year);
    sprintf(mon_str, "%d", cur_date->da_mon);
    sprintf(day_str, "%d", cur_date->da_day);

    if(cur_date->da_mon < 10)
        strcat(instr, "0");
    strcat(instr, mon_str);
    if(cur_date->da_day < 10)
        strcat(instr, "0");
    strcat(instr, day_str);
    instr[TIMESZ-1] = '\0';

    cur_time = atol(instr);
    p_time = atol(p);

    if(cur_time > p_time)
        return 1;   /* 过期 */
    else
        return -1;   /* 未过期 */
}