Re: [IBMiOSS] /QOpenSys/QOpenSys?

"OpenSource" <opensource-bounces@xxxxxxxxxxxx> wrote on 02/27/2017
11:37:19 PM:

From: Scott Klement <opensource@xxxxxxxxxxxxxxxx>
To: IBMi Open Source Roundtable <opensource@xxxxxxxxxxxx>
Date: 02/27/2017 11:37 PM
Subject: Re: [IBMiOSS] /QOpenSys/QOpenSys?
Sent by: "OpenSource" <opensource-bounces@xxxxxxxxxxxx>

All,

In my experience this comes up very often with 3rd party software that
has been compiled for AIX. The software has hard-coded paths of "/usr",

"/usr/lib", "/usr/bin" and the like -- and frequently its hard-coded
into the program.

The workaround, of course, is to use chroot. But now if you try to use
it in conjunction with software that expects /QOpenSys (such as a script

with a bang-path starting with /QOpenSys) the /QOpenSys causes it to
fail. Thus the symlink, which solves the problem.

Well, /usr/lib is already a symlink to /QOpenSys/usr/lib, so chroot is not
needed for that. The PASE loader also has fallback code in case
/usr/bin/foo is a symlink to an ILE program and look a matching
/QOpenSys/usr/bin/foo instead. The only time you should get in trouble is
if you had a shell script in /usr/bin, but you wanted the
/QOpenSys/usr/bin program/script instead.

In a perfect world, none of this stuff would be hard-coded... but
alas, the world is not perfect.

Since the symlink takes up almost no DASD, its worth having it there.

It certainly solves some problems while also causes others. The question
is whether having it there *by default* solves more problems than it
causes and how difficult it is to replace if needed. Since it's a symlink,
it's super easy to replace. The question is then whether the benefits
outweigh the downfalls and whether it is needed for anything shipped by
IBM (since shipping something broken by default is not going to fly). If I
knew for certain that no IBM i products/options relied on it, I'd take it
out of our next release and add a note to the MTU. The problem is of
course, the time to audit everything when there is more important work to
be done first.