getdate(3C) getdate(3C)
NAME
getdate - convert user format date and time
SYNOPSIS
#include <time.h>
struct tm *getdate(const char *string);
extern int getdate_err;
DESCRIPTION
getdate converts user-definable date and/or time
specifications pointed to by string into a tm structure. The
structure declaration is in the time.h header file [see also
ctime(3C)].
User-supplied templates are used to parse and interpret the
input string. The templates are text files created by the
user and identified via the environment variable DATEMSK.
Each line in the template represents an acceptable date and/or
time specification using some of the same field descriptors as
the ones used by the date command. The first line in the
template that matches the input specification is used for
interpretation and conversion into the internal time format.
If successful, the function getdate returns a pointer to a tm
structure; otherwise, it returns NULL and sets the global
variable getdate_err to indicate the error.
The following field descriptors are supported:
%% same as %
%a abbreviated weekday name
%A full weekday name
%b abbreviated month name
%B full month name
%c locale's appropriate date and time representation
%d day of month (01-31; the leading 0 is optional)
%e same as %d
%D date as %m/%d/%y
%h abbreviated month name
%H hour (00-23)
%I hour (01-12)
%m month number (01-12)
%M minute (00-59)
%n same as \n
%p locale's equivalent of either AM or PM
Copyright 1994 Novell, Inc. Page 1
getdate(3C) getdate(3C)
%r time as %I:%M:%S %p
%R time as %H:%M
%S seconds (00-59)
%t same as tab
%T time as %H:%M:%S
%w weekday number (0-6; Sunday = 0)
%x locale's appropriate date representation
%X locale's appropriate time representation
%y year within century (for example, 92)
%Y year as ccyy (for example, 1986)
%Z time zone name or no characters if no time zone exists
The month and weekday names can consist of any combination of
upper- and lowercase letters. Any strings the user puts in
are case-insensitive. For example, a string Uhr (as shown
below) would be treated the same way as a string uhr. The
user can request that the input date or time specification be
in a specific language by setting the categories LC_TIME and
LC_CTYPE of setlocale.
The following example shows the possible contents of a
template:
%m
%A %B %d %Y, %H:%M:%S
%A
%B
%m/%d/%y %I %p
%d,%m,%Y %H:%M
at %A the %dst of %B in %Y
run job at %I %p,%B %dnd
%A den %d. %B %Y %H.%M Uhr
The following are examples of valid input specifications for
the above template:
getdate("10/1/87 4 PM")
getdate("Friday")
getdate("Friday September 19 1987, 10:30:30")
getdate("24,9,1986 10:30")
getdate("at monday the 1st of december in 1986")
getdate("run job at 3 PM, december 2nd")
If the LANG environment variable is set to german, the
following is valid:
Copyright 1994 Novell, Inc. Page 2
getdate(3C) getdate(3C)
getdate("freitag den 10. oktober 1986 10.30 Uhr")
Local time and date specification are also supported. The
following examples show how local date and time specification
can be defined in the template.
Invocation | Line in Template
__________________________|__________________
getdate("11/27/86") | %m/%d/%y
getdate("27.11.86") | %d.%m.%y
getdate("86-11-27") | %y-%m-%d
getdate("Friday 12:00:00")| %A %H:%M:%S
The following rules are applied for converting the input
specification into the internal format:
If only the weekday is given, today is assumed if the
given day is equal to the current day and next week if
it is less.
If only the month is given, the current month is assumed
if the given month is equal to the current month and
next year if it is less and no year is given. (The
first day of month is assumed if no day is given.)
If no hour, minute, and second are given, the current
hour, minute, and second are assumed.
If no date is given, today is assumed if the given hour
is greater than the current hour and tomorrow is assumed
if it is less.
The following examples illustrate the above rules. Assume
that the current date is Mon Sep 22 12:19:47 EDT 1986 and that
the LC_TIME and LANG environment variables are not set.
Input | Line in Template| Date
____________|__________________|______________________________
Mon | %a | Mon Sep 22 12:19:47 EDT 1986
Sun | %a | Sun Sep 28 12:19:47 EDT 1986
Fri | %a | Fri Sep 26 12:19:47 EDT 1986
September | %B | Mon Sep 1 12:19:47 EDT 1986
January | %B | Thu Jan 1 12:19:47 EST 1987
December | %B | Mon Dec 1 12:19:47 EST 1986
Sep Mon | %b %a | Mon Sep 1 12:19:47 EDT 1986
Jan Fri | %b %a | Fri Jan 2 12:19:47 EST 1987
Copyright 1994 Novell, Inc. Page 3
getdate(3C) getdate(3C)
Dec Mon | %b %a | Mon Dec 1 12:19:47 EST 1986
Jan Wed 1989| %b %a %Y | Wed Jan 4 12:19:47 EST 1989
Fri 9 | %a %H | Fri Sep 26 09:00:00 EDT 1986
Feb 10:30 | %b %H:%S | Sun Feb 1 10:00:30 EST 1987
10:30 | %H:%M | Tue Sep 23 10:30:00 EDT 1986
13:30 | %H:%M | Mon Sep 22 13:30:00 EDT 1986
Files
/usr/lib/locale/locale/LC_TIME
language-specific printable files
/usr/lib/locale/locale/LC_CTYPE
codeset-specific printable files
Errors
On failure getdate returns NULL and sets the variable
getdate_err to indicate the error.
The following is a complete list of the getdate_err settings
and their meanings.
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 malloc failed (not enough memory is available).
7 There is no line in the template that matches the input.
8 The input specification is invalid. For example,
February 31 or a time is specified that cannot be
represented in a time_t (representing the time in seconds
since 00:00:00 UTC, January 1, 1970).
REFERENCES
ctype(3C), environ(5), setlocale(3C)
NOTICES
A simpler interface, strptime(3C), is also provided that gives
more functionality with finer control. Its use is encouraged
Copyright 1994 Novell, Inc. Page 4
getdate(3C) getdate(3C)
instead of getdate.
Subsequent calls to getdate alter the contents of getdate_err.
Dates before 1970 and after 2037 are illegal.
getdate makes explicit use of macros described in ctype(3C)
and is thus affected by the LC_CTYPE category of the current
locale.
Previous implementations of getdate may return char*.
If the time zone supplied by %Z is not the same as the time
zone getdate expects, an invalid input specification error
will result. getdate calculates an expected time zone based
on information supplied to the interface (such as hour, day,
and month).
Copyright 1994 Novell, Inc. Page 5