Mike Foster writes:
However, how can changes in the .grassrc file take effect WITHOUT
exiting and re-starting GRASS? A simple Bourne shell script (inspired by
GIS.sh) as follows does NOT do the job UNLESS Zhian exits, then restarts
GRASS:
:
g.gisenv XDRIVER_HEIGHT=
g.gisenv XDRIVER_WIDTH=
export XDRIVER_HEIGHT
export XDRIVER_WIDTH
g.gisenv XDRIVER_HEIGHT=$1
g.gisenv XDRIVER_WIDTH=$2
export XDRIVER_HEIGHT
export XDRIVER_WIDTH
eval `g.gisenv`
What silly thing have(n't) we done?
If you change those values at the GRASS prompt and then export them to your
environment, they do indeed take effect. However, if you try to change these
values by calling a script, that shell cannot update the environment of its
parent. You can issue the Unix 'env' command at your GRASS prompt to verify
this.
The relevant GRASS code for all this is
/src/display/devices/XDRIVER/XDRIVER/Graph_Set.c
It calls the function 'get_user' in order to grab these environment variables
prior to creating a monitor. If you absolutely have to resize the monitor
through a sub-shell, then it looks as if you will have to subvert this code
somehow.
--
Conn V Copas
Information Technology Division
Defence Science and Technology Organisation
PO Box 1500
Salisbury tel: +61 (0)8 25 95349
SA 5108 fax: +61 (0)8 25 96781
Australia e-mail: cvc@itd.dsto.gov.au
-------------------------------------------
Conn Copas (cvc@itd.dsto.gov.au) wrote:
: Mike Foster writes:
: >
: > However, how can changes in the .grassrc file take effect WITHOUT
: > exiting and re-starting GRASS? A simple Bourne shell script (inspired by
: > GIS.sh) as follows does NOT do the job UNLESS Zhian exits, then restarts
: > GRASS:
: >
: > :
: > g.gisenv XDRIVER_HEIGHT=
: > g.gisenv XDRIVER_WIDTH=
: > export XDRIVER_HEIGHT
: > export XDRIVER_WIDTH
: > g.gisenv XDRIVER_HEIGHT=$1
: > g.gisenv XDRIVER_WIDTH=$2
: > export XDRIVER_HEIGHT
: > export XDRIVER_WIDTH
: > eval `g.gisenv`
: >
: >
: > What silly thing have(n't) we done?
: >
: If you change those values at the GRASS prompt and then export them to your
: environment, they do indeed take effect. However, if you try to change these
: values by calling a script, that shell cannot update the environment of its
: parent. You can issue the Unix 'env' command at your GRASS prompt to verify
: this.
: The relevant GRASS code for all this is
: /src/display/devices/XDRIVER/XDRIVER/Graph_Set.c
: It calls the function 'get_user' in order to grab these environment variables
: prior to creating a monitor. If you absolutely have to resize the monitor
: through a sub-shell, then it looks as if you will have to subvert this code
: somehow.
If the problem is that the subshell does not set the environment
variables such that an 'env' will see them, the soulution is
to "source" the file rather than run it.
In bourn shell
. NeatStuff.sh
rather than
./NeatStuff.sh
In C shell
source NeatStuff.csh
rather than
./NeatStuff.csh
These operations execute the script in the current shell's process
space and do modifications (to things such as environment variables)
there. (This should be the equivilant to changeing them at the grass
prompt with set/export/setenv commands)
Dan Schmitt
Systems Analyst IEEE Member #3779402
Ranching Systems Group Phone # (409) 845-7333
Department of Rangeland Ecology and Management Fax # (409) 847-9366
Texas A&M University Home # (409) 846-3914
College Station Texas 77843-2126 ICBM: 30.67 N, 96.37 W