Multiple users of X monitors

Alan Grant Finlay alanf at
Mon Jan 18 18:03:33 EST 1993

We had exactly the same problem here.  Of course we only found out there
was a problem just days before the course was due to begin!  This is
something the Grass documentation should explain instead of letting
everyone find out for themselves.

The only solution we could find was to use a symbolic link for the lock
file and make it point to a local copy of this directory for each machine.

I didn't do all the dirty work myself but I think it only involved creating 
the symbolic link and the following change to /usr/local/grass/sgi/etc/

pi03_463% diff GIS.sh_old
< #
< # create local dev directory with named pipes in it
< # Note: $GISBASE/dev is a sym link to /usr/tmp
< #
< if [ ! -d /usr/tmp/grass ]
< then
<       mkdir /usr/tmp/grass
<       chmod 777 /usr/tmp/grass
<       chgrp grass /usr/tmp/grass
<       chown alanf /usr/tmp/grass
<       if [ ! -f $GISBASE/pipes.tar ]
<       then
<               echo $GISBASE/pipes.tar  not found
<               exit 1
<       else
<               d=`pwd`
<               cd /usr/tmp/grass
<               tar xpf $GISBASE/pipes.tar
<               cd $d
<       fi
< fi

Of course you won't want your files owned by me so you'll have to adapt this!

It was a while ago now and I don't remember exactly what happened but I think
this is all we needed to do to fix the problem.

,-------Alan Finlay, email: alanf at, phone: (03)565-5225.
|	Victorian Centre for Image Processing and Graphics,
|	Monash University, CLAYTON 3168, Australia.
`-------(Premature optimisation is the root of all evil.)

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