/*  Filename:  datecmp.c

    Author:  Br. David Carlson

    Date:  February 18, 1999

    This program compares 2 dates given in the command line parameters.
    There must be 6 such parameters in the form shown in this example:
       Jun 2, 1999 Sep 17, 2000
    The program writes an integer to standard output to indicate the
    result of the comparison: 0 if the dates are equal, -1 if the first
    is less than the second, +1 if the first is greater than the second.
    A 2 is written out if an error occurs, such as an unknown date.
*/

#include <stdio.h>
#include <strings.h>

/*  Given:  str   A 3 letter string indicating a month.
    Task:   To convert the str info into a number, using 1 for Jan, 2 for Feb,
            and so on.
    Return: This number in the function name.
*/
int GetMonth(char * str)
   {
   if (strcmp(str, "Jan") == 0)
      return 1;
   if (strcmp(str, "Feb") == 0)                                                
      return 2;                                                                
   if (strcmp(str, "Mar") == 0)                                                
      return 3;                                                                
   if (strcmp(str, "Apr") == 0)                                                
      return 4;                                                                
   if (strcmp(str, "May") == 0)                                                
      return 5;                                                                
   if (strcmp(str, "Jun") == 0)                                                
      return 6;                                                                
   if (strcmp(str, "Jul") == 0)                                                 
      return 7;                                                                 
   if (strcmp(str, "Aug") == 0)                                                 
      return 8;                                                                 
   if (strcmp(str, "Sep") == 0)                                                 
      return 9;                                                                 
   if (strcmp(str, "Oct") == 0)                                                 
      return 10;                                                              
   if (strcmp(str, "Nov") == 0)                                                 
      return 11;                                                               
   if (strcmp(str, "Dec") == 0)                                                 
      return 12;                                                               

   return 0;  // unknown month
   }


int main(int argc, char * argv[])
   {
   int MonthA, MonthB, DayA, DayB, YearA, YearB;

   if (argc != 7)
      {
      printf("%d", 2);
      exit(1);
      }

   MonthA = GetMonth(argv[1]);
   MonthB = GetMonth(argv[4]);

   if ((MonthA == 0) || (MonthB == 0))
      {
      printf("%d", 2);
      exit(1);
      }

   if (sscanf(argv[2], "%d", &DayA) != 1)
      {
      printf("%d", 2);
      exit(1);
      }              

   if (sscanf(argv[5], "%d", &DayB) != 1)                                      
      {                                                                        
      printf("%d", 2);
      exit(1);                                                                 
      }                                                                        
 
   if (sscanf(argv[3], "%d", &YearA) != 1)
      {
      printf("%d", 2);
      exit(1);
      }              

   if (sscanf(argv[6], "%d", &YearB) != 1)                                      
      {                                                                        
      printf("%d", 2);
      exit(1);                                                                 
      }                                                                        

   if (YearA < YearB)
      {
      printf("%d", -1);
      exit(0);
      }

   if (YearA > YearB)
      {
      printf("%d", 1);
      exit(0);
      }

   if (MonthA < MonthB)
      {
      printf("%d", -1);
      exit(0);
      }

   if (MonthA > MonthB)
      {
      printf("%d", 1);
      exit(0);
      }

   if (DayA < DayB)
      {
      printf("%d", -1);
      exit(0);
      }

   if (DayA > DayB)
      {
      printf("%d", 1);
      exit(0);
      }

   printf("%d", 0);   // dates must be equal if reach this point
   exit(0);
   }