#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define OVERDAY 30
long GetDateToDays(int Year,int Mon,int Day);
main()
{
   FILE *fp;
   int  Day,Mon,Year;
   long SysDays;
   long FileDays;

   time_t timep;
   struct tm *p;
   time(&timep);
   p=localtime(&timep);

   if((fp=fopen("c:\jlsj.txt","r"))==NULL)
   {
      fprintf(stderr,"error read *.txt!\n");
      exit(0);
      }
      fscanf(fp,"%d%d%d",&Year,&Mon,&Day);
      fclose(fp);


   SysDays = GetDateToDays(p->tm_year+1900,p->tm_mon,p->tm_mday);
   FileDays = GetDateToDays(Year,Mon,Day);

   if(SysDays-FileDays>=OVERDAY)
   {
 fprintf(stderr,"overday!\n");
 }
   else
 printf("inday!\n");

   printf("xitongtianshu:%ld\n",SysDays);

   printf("wenjiantianshu:%ld\n",FileDays);

  }

   long GetDateToDays(int Year,int Mon,int Day)
   {
    long Days=0;
    int  i=0,j=0;
    int  Rn[]={31,28,31,30,31,30,31,31,30,31,30,31};

    for(i=1900;i<=Year-1;i++)
    {
       if((i%4==0 && i%100!=0) || i%400==0)
       Days+=366;
       else
       Days+=365;
       }

       if((Year%4==0 && Year%100!=0) || Year%400==0)
       Rn[1]=29;
   if(Mon!=1)
   {
      for(i=0;i<Mon-2;i++)
      {
       Days+=Rn[i];
       }
       }
       Days +=Day;
       return Days;
       }

附件：/Files/welldoneyc/tc20.zip