On Tue, Jan 21, 2014 at 09:34:51AM +0100, Otto Moerbeek wrote:
> On Tue, Jan 21, 2014 at 09:08:18PM +1300, Philip Guenther wrote:
>
> > On Tue, Jan 21, 2014 at 8:33 PM, Otto Moerbeek <o...@drijf.net> wrote:
> > ...
> > > Right. what happens is that localtime(3) returns NULL, because the
> > > year is not representable as an int. struct tm.tm_year must be an int
> > > according to posix.
> > >
> > > The diff below catches the case.
> >
> > ok guenther@
> >
> >
> > > But it does not solve that 64-bit
> > > time_t can represent years that do not fit into the int sized tm_year.
> >
> > Sure, and before there was the problem that there were struct
> > localtime values that mktime() could not convert to a time_t. Lacking
> > types of fractional bit width, we have to live with one or the other,
> > no?
>
> indeed, it's one or the other.
>
> I need to check which of the time functions can returns NULL. The man
> page is awfully silent on that.
>
> -Otto
>
> >
> >
> > Philip Guenther
And here's the man page diff, our ctime and asctime actually do not
ever return NULL, while posix allows that.
-Otto
Index: ctime.3
===================================================================
RCS file: /cvs/src/lib/libc/time/ctime.3,v
retrieving revision 1.40
diff -u -p -r1.40 ctime.3
--- ctime.3 17 Jul 2013 05:42:11 -0000 1.40
+++ ctime.3 21 Jan 2014 09:43:31 -0000
@@ -257,6 +257,17 @@ is non-zero if summer time is in effect.
is the offset (in seconds) of the time represented
from UTC, with positive values indicating east
of the Prime Meridian.
+.Sh RETURN VALUES
+The functions
+.Fn localtime ,
+.Fn localtime_r ,
+.Fn gmtime
+and
+.Fn gmtime_r
+return NULL on error.
+The function
+.Fn mktime
+returns \-1 on error.
.Sh FILES
.Bl -tag -width "/usr/share/zoneinfo/posixrules" -compact
.It Pa /usr/share/zoneinfo
