Subject: Re: Caldera will publish DR DOS source code
From: adam@yggdrasil.com (Adam J. Richter)
Date: Fri, 20 Sep 1996 18:47:14 -0700 (PDT)

>> Linux/ELF certainly does support DLLs.  Shared libraries (.so's) are
>> essentially equivalent.

>I don't think so.  DLLs come with a documented, supported API that allows
>dynamic linking at run time, where both the DLL name and the entry point
>name can be computed strings.  (See my prior point about failure to
>establish stable higher-level APIs.)

	"man dlopen"

>DLLs also have explicit control over
>which names from the link get exported -- they don't automatically export
>all extern names.  This makes DLLs much more suitable as a way to package
>reusable functionality.

	You could certainly write a program to patch an ELF shared object
file to turn off export of all but a specified list of global symbols, but,
as far as I know, you are correct in that no such utility currently
exists.  Note that it would be harder to write such a utility for
static libraries because they are each stored as an archive of .o
files, but we are talking about dynamically loaded libraries here.

	I am having a little difficulty thinking of when the lack of
such a utility has actually been a problem in my own experience, but I
can see a use for it.

Adam J. Richter				  Yggdrasil Computing, Incorporated
(408) 261-6630				  "Free Software For The Rest of Us."