The rleapyear() function

The demo directory contains this sample program in the rleapyear.ec file.

/*
   * rleapyear.ec *

   The following program accepts a date entered from the console 
   and stores this date into an int4, which stores the date in
   an internal format. It then converts the internal format into an array of
   three short integers that contain the month, day, and year portions of the 
   date. It then tests the year value to see if the year is a leap year.
*/

#include <stdio.h>

main()
{
   int4 i_date;
   mint errnum;
   short mdy_array[3];
   char date[20];
   mint x;

   static char fmtstr[9] = "mmddyyyy";

   printf("RLEAPYEAR Sample Program running.\n\n");

    /* Allow user to enter a date */
   printf("Enter a date as a single string, month.day.year\n");
   gets(date);

   printf("\nThe date string is %s.\n", date);

   /* Put entered date in internal format */
   if (x = rdefmtdate(&i_date, fmtstr, date))
      printf("Error %d on rdefmtdate conversion\n", x);
   else
      {

      /* Convert internal format into a MDY array */
      if ((errnum = rjulmdy(i_date, mdy_array)) == 0)
         {
         /* Check if it is a leap year */
         if (rleapyear(mdy_array[2]))
            printf("%d is a leap year\n", mdy_array[2]);
         else
            printf("%d is not a leap year\n", mdy_array[2]);
         }
      else
         printf("rjulmdy() call failed with error %d", errnum);
      }

    printf("\nRLEAPYEAR Sample Program over.\n\n");
}