[GRASS5] some thoughts

[Roger Miller]

On Thu, 17 Jan 2002, Glynn Clements wrote:
  
> In order to be able to implement a proper GUI (as well as things like
> a web interface), the core programs have to cease using G_ask_*,
> R_get_location_with_*, stdin, stdout, stderr, etc. Instead, they need
> to just parse the command line, read data, perform computation, write
> data, and exit.

I wasn't grumbling about the user interface, much less about the GUI.  I
use the command line interface, because GUI's don't work well over a slow
network link and I often work from home over a 56K modem. Removing the
terminal interface from the commands would destroy much of the value in
GRASS.  On the other hand, you could rewrite the parser to eliminate some
the interactive prompts and it wouldn't bother me at all.

My suggestion was that a layer (running as a user-space daemon) should be
inserted in the libraries.  That layer would be responsible for managing
the user's run-time environment and coordinating between different tasks.  
The user would no longer need to micro-manage his own environment, and
some variables (location, for instance) could be changed on the fly. Other
variables (like the region settings) could be altered by one user without
effecting other users, making simultaneous access a more realistic
possibility.

I think the new layer could be built into the exiting GRASS architecture
without breaking any of the existing functionality.  The initial version
would be simple and have a minimal role. Additional library routines could
be rewritten to use the added layer as time goes by.


Roger Miller