Subject: Re: compat_ultrix
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: Jonathan Stone <jonathan@DSG.STANFORD.EDU>
List: port-pmax
Date: 02/05/1996 20:27:26
In message <199602060324.TAA12051@lestat.nas.nasa.gov>Jason Thorpe writes
>
>When running an Ultrix executable, /emul/ultrix will be checked first for 
>everything.  (depending on how many syscalls it's used in, that is...)

hmm.  An Ultrix binary for xdm (x11R6pl13 or thereabouts) has a pathname
for the C preprocessor hard-coded into it, so it can preprocess its
resource file (e.g., /usr/X11R6/lib/xdm/xdm-config.)

If, on a pmax kernel with COMPAT_ULTRIX, I do
 '( mkdir /emul/ultrix/lib; ln -s /usr/libexec/cpp  /emul/ultrix/lib/cpp cpp)'

then both an Ultrix  ls and an Ultrix xdm can see that there's a /lib/cpp
in the emul_ultrix namespace, but neither of them can  exec the cpp script,
or follow the symlink and stat it (e.g., via ls -L).

Is this the intended semantics of /emul?  Is it well thought-out?
Is it a bug?

(I don't know, but if this were a democracy, I'd put in a "yes" vote for the
last option :))