disabling 'insecure' parts of gnuplot file

[Edward P. <es...@pg...>]

hey all,

I'm writing an application whose intent is to take a gnuplot file, turn it into a
PNG graph, and then display that graph online.

Anyway, I would like to therefore disable anything that gnuplot can do outside of 
drawing graphs, for example:

!rm -rf /

considering that I don't want someone to upload something to wipe out my 
system (or even try)..

Also - I was wondering - is there a good format that people would suggest to 
make any and all plots self-contained? I'd like something like:

	- one plot per graph file

	- forcing of png format

	- data and plot statement in the same file

yet the plot statemnts (at least for data) tend to be of the form

plot [x1:x2] [y1:y2] "filename"

How can you make it so that the plot statement refers to itself, ie a dataset in the 
file itself?

Ed