Date: Tue, 24 Jun 1997 09:42:03 +0300 (IDT)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: DJ Delorie <dj AT delorie DOT com>
cc: broeker AT physik DOT rwth-aachen DOT de, djgpp-workers AT delorie DOT com
Subject: Re: Library rebuilds
In-Reply-To: <199706232351.TAA27480@delorie.com>
Message-ID: <Pine.SUN.3.91.970624094135.8435C-100000@is>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk


On Mon, 23 Jun 1997, DJ Delorie wrote:

> > Hey, maybe that's what I should do... install even 'libc.a' using
> > 'update', and then let make call itself until it libc.a stops to change,
> > and only then allow 'make install'. But I'm slowly loosing my footing
> > here, I think :-)
> 
> COFF objects have timestamps in them.  Beware when constructing loops
> like this, because a binary compare won't ever compare two objects the
> same, if they were built at different times.

These timestamps somehow go away when they are linked into an
executable, right?  Because binary compare of .exe programs *does*
work for me.

Anyway, for .o and .a files you could use `dd' (from Textutils) with
its `skip=' and `seek=' options to skip parts of the files that have
time-dependent info and *then* compare with `cmp' or `update'.  I am
assuming here that the parts with the timestamps have constant size.