running ferret from a CGI script

[Rodrigo Caballero <rca@xxxxxxxxxxxxxxxxxxx>]

Hello,

I have a somewhat technical question that I hope someone can help me 
with.

I'm trying to call ferret from a CGI script in order to read some data, 
make a simple XY plot, plot it out to gif file, and then send the gif 
back to the browser client. The CGI script sets up all the ferret 
environment variables and then does

ferret -gif < foo.jnl > /tmp/ferret.log,

where foo.jnl is simply:

file/skip=2/var=hour,toasw "/tmp/diurnal"
plot/vs/line hour,toasw
frame/file="/tmp/foo.gif"

This works fine when I do it from the command line, but when I do it 
from the CGI script I get the following error:

**ERROR: .gif: Permission denied
gsetcolourrep()    7 GKS not in proper state: GKS shall be in one of 
the states WSOP, WSAC or SGOP
gupdatews()    7 GKS not in proper state: GKS shall be in one of the 
states WSOP, WSAC or SGOP
gclearws()    6 GKS not in proper state: GKS shall be either in the 
state WSOP or in the state WSAC
ginqwsconntype()    7 GKS not in proper state: GKS shall be in one of 
the states WSOP, WSAC or SGOP
gsetwswindow()    7 GKS not in proper state: GKS shall be in one of the 
states WSOP, WSAC or SGOP
gescsetdcsize()    7 GKS not in proper state: GKS shall be in one of 
the states WSOP, WSAC or SGOP
gupdatews()    7 GKS not in proper state: GKS shall be in one of the 
states WSOP, WSAC or SGOP
 **ERROR: required program command has not been given: graphical output 
device isnt ready

I guess I should really be using the LAS, but I'd rather not get 
involved in those intricacies. Any suggestions?

Thanks,
Rodrigo

---

Rodrigo Caballero Augi (http://geosci.uchicago.edu/~rca)
Research Associate
Department of the Geophysical Sciences, University of Chicago
5734 South Ellis Avenue, Chicago, IL 60637, USA.