Re: Trying to use AUTHOR_DATE

From: Russ Allbery <rra@stanford.edu>
Date: Apr 30, 2005, 18:10 UTC
Message-ID: <87r7gs87a9.fsf@windlord.stanford.edu>
In-Reply-To: <20050430124048.79119cac.froese@gmx.de>

Edgar Toernig <froese@gmx.de> writes:

> Oh btw, when we are about sucking time functions: the %s and %z
> strftime- sequences used further down are also non-standard (POSIX has
> no %s, old libc has neither %s nor %z).

> A possible workaround:

[...]

> 	tm = localtime(&now); /* get timezone and tm_isdst */
> 	tz = -timezone / 60;
> 	if (tm->tm_isdst > 0)
> 		tz += 60;

The global timezone variable isn't available on all systems.  :)

You really cannot get portable behavior in this area without something akin to Autoconf probes, unfortunately. Oh, and you can't assume daylight savings time is an hour; it is sometimes two hours. You have to instead use the altzone variable to get the offset when you're in daylight savings time, but this again isn't available on all systems.

I posted a pointer to the INN source a while back; I'm really not sure that anything less is sufficient to get full portability, although I certainly trust Paul Eggart's implementation.

BTW, the yacc-based thing is exactly what I wrote the INN code to get rid of, since I didn't want a yacc dependency.

-- 
Russ Allbery (rra@stanford.edu)             <http://www.eyrie.org/~eagle/>