[R] RE: Xvfb and R

[michael watson (IAH-C)]

Forgive that last mail, I have now realised it was all complete b*ll*cks ;-)

-----Original Message-----
From: michael watson (IAH-C) 
Sent: 07 July 2003 15:12
To: 'r-help at stat.math.ethz.ch'
Subject: Xvfb and R


Hi

I have recently installed and implemented Xvfb (X virtual frame buffer) so that I can create jpegs using R over CGI (SUSE Linux 8.1 and Apache 1.3).

I have noticed that in order to do this, a file (Rplots.ps) is created in my cgi-bin directory everytime a cgi script is run.  This could cause problems though as I have a multi-user system where it is possible that two different users will run cgi scripts at the same time, and both will be writing/reading Rplots.ps at the same time - a conflict!

I am simply using the jpeg() function of R.  On a different server, where I'm not using Xvfb but the real X server, I do not get this fule Rplots.ps so I am guessing that there is some magic going on behind the scenes, though I may be wrong.

Can anyone explain what is happening, and if I can make R/Xvfb create a DIFFERENT file, say in /tmp/, with a unique name, everytime a cgi script is run?

Cheers
Mick

Michael Watson
Head of Informatics
Institute for Animal Health,
Compton Laboratory,
Compton,
Newbury,
Berkshire RG20 7NN
UK

Phone : +44 (0)1635 578411 ext. 2535
Mobile: +44 (0)7764 490236
E-mail: michael.watson at bbsrc.ac.uk