Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!apple!fernwood!lia!steve
From: steve@lia (Stephen Williams)
Newsgroups: comp.windows.x
Subject: Re: Sun shared libs - openwin vs MIT R4
Message-ID: <1991May10.010143.7028@lia>
Date: 10 May 91 01:01:43 GMT
References: <1991May8.210941.4846@watdragon.waterloo.edu>
Reply-To: steve@lia.com (Stephen Williams)
Organization: Litton/Integrated Automation, Alameda, California
Lines: 40

In article <1991May8.210941.4846@watdragon.waterloo.edu> jmsellens@watdragon.waterloo.edu (John M. Sellens) writes:
>Sun, in their wisdom, forces OpenWindows users to set LD_LIBRARY_PATH
>in order to find the shared libraries in /usr/openwin/lib, instead of
>putting them somewhere normal, like /usr/lib for example, or using an
>appropriate -L on the cc command line when they link the applications.
>

I too have fought this battle.

>I have the MIT shared libraries somewhere else (doesn't really matter where).
>I'm having trouble convincing my MIT binaries to ignore LD_LIBRARY_PATH,
>and use the library paths that I gave them when I linked them.  I checked
>the FAQ, but it didn't seem to answer this question.

Here are the rules:

  At link time, the compiler uses the -L switches to search directories
for libraries.  If this fails, then the LD_LIBRARY_PATH variable is searched.
The paths passed to ld are stored in the object file.

  At run time, LD_LIBRARY_PATH is search FIRST for needed libraries.  If
this search fails then the stored directories are searched.  If you ask me,
this is brain-damage for sure, but I suppose someone had a good reason for
this.

  The mess happens when two libraries from 2 different packages (MIT X11
and OpenLook, for example) exist.  If the libraries are in different places,
and can be found with encoded -L paths, and are NOT in any directories in
the LD_LIBRARY_PATH, then all is well.  However, if LD_LIBRARY_PATH
contains a directory that has a copy of said shared object ...  oh well.

  There are 2 solutions. (Actually 3, but the third is not polite.)  First,
you can make little shell scripts for all your OPENLOOK tools that munge
the LD_LIBRARY_PATH just for them.  Alternatively, you can use strings -a
to find the paths that were used to find the libraries when they were linked,
and you can put symbolic links there.  Either way, you will no longer need
LD_LIBRARY_PATH set.  (By the way, I think /Proto/4.0/Xnews/sun4/usr/lib
will probably work.)

--Steve