[GRASS5] Running multiple commands

[Glynn Clements]

Gualter Barbas Baptista wrote:

> What's the best way to run multiple commands in GRASS? What I'm doing 
> now is trying to put the tasks to background with the &, but then I 
> still get the input on the console, which gets things really confusing.
> Is it possible, for example, to start another GRASS command line on 
> another terminal?
> 
> The reason why I want to do this is to be able to process two different 
> modules simultaneously in an openMOSIX cluster and be able to see where 
> each one is standing.

The GRASS startup scripts won't allow multiple sessions for the same
user (to prevent race conditions in reading/writing $GISRC), or for a
given mapset (to prevent race conditions in reading/writing the
mapset; note that this applies not just to maps, but to the WIND,
[CUR]GROUP and [CUR]SUBGROUP files and to temporary files).

You can bypass the startup, and just set the necessary environment
variables yourself, e.g.

	GISBASE=/opt/grass5
	GISRC=$HOME/.grassrc5
	TCLTKGRASSBASE=$GISBASE/tcltkgrass
	
	GRASS_GNUPLOT=gnuplot
	GRASS_PAGER=cat
	GRASS_PERL=perl
	GRASS_TCLSH=tclsh
	GRASS_WISH=wish
	
	PATH=$GISBASE/bin:$GISBASE/scripts:$PATH
	MANPATH=$GISBASE/man:$MANPATH
	LD_LIBRARY_PATH=$GISBASE/lib:$LD_LIBRARY_PATH
	
	PAGER=cat
	
	export GISBASE GISRC TCLTKGRASSBASE
	export GRASS_GNUPLOT GRASS_PAGER GRASS_PERL GRASS_TCLSH GRASS_WISH
	export PATH MANPATH LD_LIBRARY_PATH
	export PAGER

You should give each process a different $GISRC file, using different
mapsets (and, if applicable, different monitors).

-- 
Glynn Clements <glynn.clements at virgin.net>