alleg-developers

[AD] 3.9.33 Unix patch (non-root users and ld.so.conf advice)

[George F. <gf...@us...>]

Hi,

I've modified the Unix makefile so that if it's installing
shared libraries it checks that the target directory is listed
in /etc/ld.so.conf, and if not it prints a warning that programs
may not run in this state.  The main motivation for this is that
many Linux distributions don't have /usr/local/lib listed in
/etc/ld.so.conf.  I also changed the order of installation
so that the warning is visible when the installation finishes.

I also modified `readme.uni' to include more details of how to
install Allegro when you don't have root access to the system,
which is sort of related to the above problem.  I updated the
information about depending on other libraries like X, GGI, and
SVGAlib.

I'm not sure whether the test on /etc/ld.so.conf is appropriate
for other platforms, so if anybody uses one it'd be good to know
whether this should only occur on Linux systems, and also
whether the LD_LIBRARY_PATH environment variable is universal or
Linux-specific.

Something else I considered was adding an option to
`allegro-config' which would make it output a string of
environment variable modifications, for use when Allegro is not
installed to the usual place.  It's an easy change; the idea
then is that instead of putting all the modifications in their
.bash_profile, they just have to add (or type themselves):

    `allegro_config --env`

I didn't implement this, but I can if people think it would be
useful.  It's true that not many people use Allegro without
having root access to machines -- unless you have console access
to a machine you can't do graphics efficiently, and if you have
console access you probably know the owner of the machine anyway
-- but there have been people asking about this in the past.

I'm attaching a diff for everything apart from `allegro-config'.

George

-- 
Random project update:
22/06/2000: AllegroGL documentation:  http://allegrogl.sourceforge.net/
        See under `Documentation' for the AllegroGL Reference Manual in
        various formats.

Re: [AD] 3.9.33 Unix patch (non-root users and ld.so.conf advice)

[George F. <gf...@us...>]

On Sun, Oct 15, 2000 at 09:15:00PM +0100, George Foot wrote:
> Something else I considered was adding an option to
> `allegro-config' which would make it output a string of
> environment variable modifications, for use when Allegro is not
> installed to the usual place.

I have now done this, and updated the documentation again.

George

-- 
Random project update:
09/05/2000: Libnet 0.10.8 uploaded -- a few bugfixes
        http://www.canvaslink.com/libnet/  (try changes-0.10.8.txt)

Re: [AD] 3.9.33 Unix patch (non-root users and ld.so.conf advice)

[Laurent D. <l-d...@ti...>]

George Foot wrote:
> 
> I'm not sure whether the test on /etc/ld.so.conf is appropriate
> for other platforms, so if anybody uses one it'd be good to know
> whether this should only occur on Linux systems, and also
> whether the LD_LIBRARY_PATH environment variable is universal or
> Linux-specific.

   Under Solaris 2.5.1 and Solaris 7, /etc/ld.so.conf does
not exist.  In fact, these systems rely only upon
LD_LIBRARY_PATH (though I may be wrong...).

   Under HP-UX 10.20, LD_LIBRARY_PATH doest not even exist,
it's called SHLIB_PATH.  But since it defaults to empty, I
guess there's a file somewhere or it has a built-in list of
paths (for security reasons).

   Yep, I know these OSes are exotic ;)


		Laurent

Re: [AD] 3.9.33 Unix patch (non-root users and ld.so.conf advice)

[George F. <gf...@us...>]

On Mon, Oct 16, 2000 at 08:47:42AM +0200, Laurent Desnogues wrote:
> George Foot wrote:
> > 
> > I'm not sure whether the test on /etc/ld.so.conf is appropriate
> > for other platforms, so if anybody uses one it'd be good to know
> > whether this should only occur on Linux systems, and also
> > whether the LD_LIBRARY_PATH environment variable is universal or
> > Linux-specific.
> 
>    Under Solaris 2.5.1 and Solaris 7, /etc/ld.so.conf does
> not exist.  In fact, these systems rely only upon
> LD_LIBRARY_PATH (though I may be wrong...).
> 
>    Under HP-UX 10.20, LD_LIBRARY_PATH doest not even exist,
> it's called SHLIB_PATH.  But since it defaults to empty, I
> guess there's a file somewhere or it has a built-in list of
> paths (for security reasons).
> 
>    Yep, I know these OSes are exotic ;)

We ought to support them if possible though. :)

Any ideas what we should do about this then?  One thing is to
only perform this test on Linux, which is probably the most
common Unixy OS used with Allegro.  If /etc/ld.so.conf really is
only used in Linux, we should only check it there.  It might be
better to only perform the test if the file exists, to cater for
any other OSes using that system without having to know about
them specifically, but that would break if some OS uses that
file in a different way.

We should probably also check in LD_LIBRARY_PATH, since if the
target directory is already there then we don't need to
complain.  This would then work on Solaris, but not HP-UX.  We
could test in $LD_LIBRARY_PATH:$SHLIB_PATH.  Hmm.

If we find that the target directory isn't in any of these
things, we also need to give the user a little guidance as to
how to add it (in particular, where to add it!).  In Linux,
/etc/ld.so.conf is the appropriate place for doing it globally,
and for a single user (or if you don't have root access) it's
LD_LIBRARY_PATH.  I guess in Solaris for a permanent global
solution you need to find where LD_LIBRARY_PATH is first set, or
just stick something it /etc/profile to update it.  I'm not sure
how far we should go in this direction though; to some extent,
people running weird OSes ought to know how to use them. :) It's
only a problem with Linux because it's so much trying to target
the less knowledgable users these days.

If we do go into any depth, the deep stuff should be hidden away
in readme.uni and the error message should only mention a couple
of things and point to the longer description in case the user
is interested in that.

George

-- 
Random project update:
22/06/2000: AllegroGL documentation:  http://allegrogl.sourceforge.net/
        See under `Documentation' for the AllegroGL Reference Manual in
        various formats.