The rdefmtdate() function

Syntax

mint rdefmtdate(jdate, fmtstring, inbuf)
   int4 *jdate;
   char *fmtstring;
   char *inbuf;

jdate

A pointer to a int4 integer value that receives the internal DATE value for the inbuf string.

fmtstring

A pointer to the buffer that contains the formatting mask to use the inbuf string.

inbuf

A pointer to the buffer that contains the date string to convert.

Usage

The fmtstring argument of the rdefmtdate() function points to the date-formatting mask, which contains formats that describe how to interpret the date string. For more information about these date formats, see Format date strings

The input string and the fmtstring must be in the same sequential order in terms of month, day, and year. They need not, however, contain the same literals or the same representation for month, day, and year.

You can include the weekday format (ww), in fmtstring, but the database server ignores that format. Nothing from the inbuf corresponds to the weekday format.

The following combinations of fmtstring and input are valid.

Formatting mask

Input

mmddyy

Dec. 25th, 2007

mmddyyyy

Dec. 25th, 2007

mmm. dd. yyyy

dec 25 2007

mmm. dd. yyyy

DEC-25-2007

mmm. dd. yyyy

122507

mmm. dd. yyyy

12/25/07

yy/mm/dd

07/12/25

yy/mm/dd

2007, December 25

yy/mm/dd

In the year 2007, the month of December, it is the 25th day

dd-mm-yy

This 25th day of December 2007

If the value stored in inbuf is a four-digit year, the rdefmtdate() function uses that value. If the value stored in inbuf is a two-digit year, the rdefmtdate() function uses the value of the DBCENTURY environment variable to determine which century to use. If you do not set DBCENTURY, Informix® ESQL/C uses the 20th century. For information about how to set DBCENTURY, see the Informix® Guide to SQL: Reference.

Return codes

Example

/*
   * rdefmtdate.ec *

   The following program accepts a date entered from the console,
   converts it into the internal date format using rdefmtdate().
   It checks the conversion by finding the day of the week.
*/

#include <stdio.h>

main()
{
    mint x;
    char date[20];
    int4 i_date;
    char *day_name;

    static  char fmtstr[9] = "mmddyyyy";

   printf("RDEFMTDATE Sample ESQL Program running.\n\n");

    printf("Enter a date as a single string, month.day.year\n");
    gets(date);

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

    if (x = rdefmtdate(&i_date, fmtstr, date))
       printf("Error %d on rdefmtdate conversion\n", x);
    else
      {
        /* Figure out what day of the week i_date is */
      switch (rdayofweek(i_date))
         {
         case 0:   day_name = "Sunday"; 
               break;
         case 1:   day_name = "Monday";
               break;
         case 2:   day_name = "Tuesday";
               break;
         case 3:   day_name = "Wednesday";
               break;
         case 4:   day_name = "Thursday";
               break;
         case 5:   day_name = "Friday";
               break;
         case 6:   day_name = "Saturday";
               break;
         }
      printf("\nThe day of the week is %s.\n", day_name);
      }

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

Output

RDEFMTDATE Sample ESQL Program running.

Enter a date as a single string, month.day.year
080894

The date string is 080894
The day of the week is Monday.

RDEFMTDATE Sample Program over.