'Safe' version for the web?

[Neal Holtz]

I teach a first course in Numerical Methods to about 200 2nd year
engineering students each term.  This year my expectation was that
students use Matlab, mostly because I wasn't comfortable with the
plotting solution on Win95 (its quite adequate for my purposes
on Linux).  This fall I hope to be able to expect students to use
Octave instead; I'm willing to spend time in the summer to help bring
this about.

My point (and I do have one): I would like a 'safe' version of octave
that I could run from a web server - file i/o and system primitives
and environment queries disabled; greatly reduced libraries; perhaps
run in a chrooted environment; diagnostics when some functions such as
plot(), input(), etc called.  Perhaps invoked via command line option
like '--safe' or something.  I'm not asking anyone to do anything
about this - I'm quite willing to do the work myself.  But if others
could think about it, suggest things, etc ...  Its quite possible that
I could start doing things more actively in a couple of weeks.

Reason:  this year, as part of their homework assignments, I have asked
students to submit m-files via the web.  I grade them semi-automatically
by running them carefully through Matlab, and comparing answers with
expected answers.  The students can review the electronic marking via
the web; it comes with quite a few explanations.  Relax - all grades
are also reviewed by human markers, but they don't have to spend much
time on the ones that pass all the tests.  And this is only a part of the
mark (usually about 60% for normal paper submission, and 40% for electronic
Matlab submission).  

It worked well enough this term that I will continue.  Next term,
because students are notoriously bad at following precise instructions
about function interfaces; I will let them review their submission 
immediately after the deadline, and resubmit a small number of times,
with increasing penalty for each resubmission.  Thus the need for an
octave CGI (or Matlab, if I have to).  And I would be a lot more
comfortable with a 'safe' version, even though a lot can be accomplished
by running the server under a user ID that has almost no priveledges.

cheers
neal

-- 
Neal Holtz                             http://www.docuweb.ca/~nholtz
Dept. of Civil and Environmental Engineering,   Carleton University,   
Ottawa, Ontario, Canada K1S 5B6.                   address@hidden