getdate

GETDATE(3)		  Linux Programmer’s Manual		   GETDATE(3)



NAME
       getdate() - convert a string to struct tm

SYNOPSIS
       #define _XOPEN_SOURCE
       #define _XOPEN_SOURCE_EXTENDED
       #include <time.h>

       struct tm *getdate (const char *string);

       extern int getdate_err;


       #define _GNU_SOURCE
       #include <time.h>

       int getdate_r (const char *string, struct tm *res);

DESCRIPTION
       The function getdate() converts a string pointed to by string into the
       tm structure that it returns.  This  tm	structure  may	be  found  in
       static storage, so that it will be overwritten by the next call.

       In  contrast  to strptime(3), (which has a format argument), getdate()
       uses the formats found in the file of which  the	 full  path  name  is
       given in the environment variable DATEMSK.  The first line in the file
       that matches the given input string is used for the conversion.

       The matching is	done  case  insensitively.   Superfluous  whitespace,
       either in the pattern or in the string to be converted, is ignored.

       The  conversion	specifications	that  a pattern can contain are those
       given for strptime(3).  One more conversion specification is accepted:

       %Z     Timezone name.

       When  %Z is given, the value to be returned is initialised to the bro-
       ken-down time corresponding to the current  time	 in  the  given	 time
       zone.   Otherwise,  it  is  initialised to the broken-down time corre-
       sponding to the current local time.

       When only the weekday is given, the day is taken to be the first	 such
       day on or after today.

       When  only  the month is given (and no year), the month is taken to be
       the first such month equal to or after the current month.  If  no  day
       is given, it is the first day of the month.

       When  no	 hour,	minute and second are given, the current hour, minute
       and second are taken.

       If no date is given, but we know the hour, then that hour is taken  to
       be the first such hour equal to or after the current hour.

RETURN VALUE
       When successful, this function returns a pointer to a struct tm.	 Oth-
       erwise, it returns NULL and  sets  the  global  variable	 getdate_err.
       Changes	to  errno  are	unspecified.   The  following values for get-
       date_err are defined:

       1   The DATEMSK environment variable is null or undefined.

       2   The template file cannot be opened for reading.

       3   Failed to get file status information.

       4   The template file is not a regular file.

       5   An error is encountered while reading the template file.

       6   Memory allocation failed (not enough memory available).

       7   There is no line in the file that matches the input.

       8   Invalid input specification.

NOTES
       Since getdate() is not reentrant because of the use of getdate_err and
       the  static  buffer  to return the result in, glibc provides a thread-
       safe variant.  The functionality is the same.  The result is  returned
       in  the	buffer	pointed	 to by res and in case of an error the return
       value is nonzero with the same values as given above for	 getdate_err.

       The POSIX 1003.1-2001 specification for strptime() contains conversion
       specifications using the %E or %O modifier, while such  specifications
       are not given for getdate().  The glibc implementation implements get-
       date() using strptime() so that automatically precisely the same	 con-
       versions are supported by both.

       The glibc implementation does not support the %Z conversion specifica-
       tion.

ENVIRONMENT
       DATEMSK
	      File containing format patterns.

       TZ, LC_TIME
	      Variables used by strptime().

CONFORMING TO
       ISO 9899, POSIX 1003.1-2001

SEE ALSO
       localtime(3), strftime(3), strptime(3), time(3)



				  2001-12-26			   GETDATE(3)