GETDATE(3) Library Functions Manual GETDATE(3)
getdate, getdate_err -- convert user format date and time
Standard C Library (libc, -lc)
struct tm *
getdate(const char *str);
extern int getdate_err;
The getdate() function converts a date or time character string pointed
to by str into a static tm structure described in tm(3).
The input string is parsed and interpreted using templates. A text file
containing templates is specified by the environment variable DATEMSK.
This should contain the full path to the template file. Lines in the
template file represent acceptable date and/or time conversion
specifications. These specifications are similar to those given for
strptime(3). The first line in the template file that matches the input
string is used to interpret and convert to internal time format.
Internal Format Conversion
The following rules apply to converting the input into the internal
o If only the weekday is given, the conversion assumes today when
the weekday matches today or the first future matching weekday.
o If only the month and no year is given, the conversion assumes
the current month when the month matches or the first future
matching month. The first day of the month is assumed if no
day is given.
o If only the year is given, the values of the tm_mon, tm_mday,
tm_wday, tm_yday, and tm_isdst members of the returned struct
tm are unspecified.
o If the century is given, but the year within the century is not
given, the conversion assumes the current year.
o If no hour, minute, and second are given, the conversion
assumes the current hour, minute, and second.
o If no date is given, the conversion assumes today when the
given hour is greater than the current hour and tomorrow when
the given hour is less.
o If %Z is being scanned, then the broken-down time is based on
the the current time of the matched timezone and not the
current runtime environment timezone.
If successful, the getdate() function returns a pointer to a static tm
structure containing the broken-down time. Otherwise, a null pointer is
returned and getdate_err is set to indicate the error.
The variable getdate_err can have the following values:
1 DATEMSK environment variable is null or undefined.
2 Cannot open the template file for reading.
3 Get file status failed for template file.
4 Template file is not a regular file.
5 Encountered an error while reading the template file.
6 Cannot allocate memory.
7 Input string does not match any line in the template file.
8 Input string is invalid (for example February 31) or could not be
represented in a time_t.
DATEMSK The full path to the text file containing the templates for
acceptable date and/or time conversions.
An example template file that could be specified via the DATEMSK
The following example shows the possible contents of a template file:
%A %B %d, %Y, %H:%M:%S
%m/%d/%y %I %p
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 for the above template:
10/1/87 4 PM
Firday September 18, 1987, 10:30:30
at monday the 1st of december in 1986
run job at 3 PM, december 2nd
The following examples show how local data and time specification can be
defined in the template.
Input String Line in Template
Friday 12:00:00 %A %H:%M:%S
The following examples illustrate the Internal Format Conversion rules
given that the current date is Mon Sep 22 12:19:47 EDT 1986 and the
LC_TIME environment variable is set to the default C locale.
Input String Line in Template Date
Mon %a Mon Sep 22 12:19:47 EDT
Sun %a Sun Sep 28 12:19:47 EDT
Fri %a Sun Sep 26 12:19:47 EDT
September %B Mon Sep 1 12:19:47 EDT
January %B Thu Jan 1 12:19:47 EST
December %B Mon Dec 1 12:19:47 EST
Sep Mon %b %a Mon Sep 1 12:19:47 EDT
Jan Fri %b %a Fri Jan 2 12:19:47 EDT
Dec Mon %b %a Mon Dec 1 12:19:47 EDT
Jan Wed 1989 %b %a %Y Wed Jan 4 12:19:47 EST
Fri 9 %a %H Fri Sep 26 09:00:00 EDT
Feb 10:30 %b %H:%S Sun Feb 1 10:00:30 EST
10:30 %H:%M Tue Sep 23 10:30:00 EDT
13:30 %H:%M Tue Sep 22 13:30:00 EDT
ctime(3), localtime(3), mktime(3), strftime(3), strptime(3), time(3)
The getdate() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').
The getdate function appeared in AT&T System V Release 4 UNIX.
The getdate interface is inherently unsafe for multi-threaded programs or
libraries, since it returns a pointer to a static variable and uses a
global state variable.
NetBSD 6.1.5 April 14, 2011 NetBSD 6.1.5