Provided by: grass-core_7.8.2-1build3_amd64 
GRASS startup program
SYNOPSIS
grass78 [-h | -help | --help] [-v | --version] | [-c | -c geofile | -c EPSG:code[:datum_trans]] | -e | -f
| [--text | --gtext | --gui] | --config | --exec EXECUTABLE | --tmp-location [[[<GISDBASE>/]<LOCATION>/]
<MAPSET>]
Flags:
-h | -help | --help
Prints a brief usage message and exits
-v | --version
Prints the version of GRASS and exits
-c
Creates new GRASS unprojected location in specified GISDBASE
-c geofile
Creates new GRASS projected location in specified GISDBASE based on georeferenced file
-c EPSG:code
Creates new GRASS projected location in specified GISDBASE with given EPSG code
-c EPSG:code:datum_trans
Creates new GRASS projected location in specified GISDBASE with given EPSG code and datum transform
parameters
-e
Exit after creation of location or mapset. Only with -c flag
-f
Forces removal of .gislock if exists (use with care!). Only with --text flag
--text
Indicates that Text-based User Interface should be used (skip welcome screen)
--gtext
Indicates that Text-based User Interface should be used (show welcome screen)
--gui
Indicates that Graphical User Interface (wxGUI) should be used
--config
Prints GRASS configuration parameters (options: arch, build, compiler, path, revision)
--exec EXECUTABLE
Execute GRASS module or script. The provided executable will be executed in a GRASS GIS
non-interactive session.
--tmp-location
Run using a temporary location which is created based on the given coordinate reference system and
deleted at the end of the execution (use the --exec flag). The active mapset will be PERMANENT.
Parameters:
GISDBASE
Initial database directory which should be a fully qualified path (e.g., /usr/local/share/grassdata)
LOCATION
Initial location directory which is a subdirectory of GISDBASE
MAPSET
Initial mapset directory which is a subdirectory of LOCATION Note: These parameters must be specified
in one of the following ways:
MAPSET
LOCATION/MAPSET
GISDBASE/LOCATION/MAPSET
DESCRIPTION
This command is used to launch GRASS GIS. It will parse the command line arguments and then initialize
GRASS for the user. Since GRASS modules require a specific environment, this program must be called
before any other GRASS module can run. The command line arguments are optional and provide the user with
a method to indicate the desired user interface, as well as the desired mapset to work on.
The startup program will remember both the desired user interface and mapset. Thus, the next time the
user runs GRASS, typing grass78 (without any options) will start GRASS with the previous settings for the
user interface and mapset selected.
If you specify a graphical user interface (--gui) the grass78 program will try to verify that the system
you specified exists and that you can access it successfully. If any of these checks fail then grass78
will automatically switch back to the text user interface mode.
SAMPLE DATA
The GRASS GIS project provides several free sample geospatial datasets as ready-to-use locations. They
are available to download at https://grass.osgeo.org/download/sample-data/. The "North Carolina data
set" is a modern package of geospatial data from North Carolina (USA), and it includes raster, vector,
LiDAR and satellite data. This is the most extensively used data set in the documentation and the
examples throughout the user manual pages are based upon it.
ENVIRONMENT VARIABLES
A number of environment variables are available at GRASS startup to assist with automation and
customization. Most users will not need to bother with these.
In addition to these shell environment variables GRASS maintains a number of GIS environment variables in
the $HOME/.grass7/rc file. User changes to this file will be read during the next startup of GRASS. If
this file becomes corrupted the user may edit it by hand or remove it to start afresh. See the list of
implemented GRASS variables for more information. The rest of this help page will only consider shell
environment variables.
Note that you will need to set these variables using the appropriate method required for the UNIX shell
that you use (e.g. in a Bash shell you must export the variables for them to propagate).
User Interface Environment Variable
The grass78 program will check for the existence of an environment variable called GRASS_GUI which
indicates the type of user interface for GRASS to use. If this variable is not set when grass78 is run,
then it will be created and then saved in the $HOME/.grass7/rc file for the next time GRASS is run. It
can be set to text, gtext or gui.
There is an order of precedence in the way grass78 determines the user interface to use. The following is
the hierarchy from highest precedence to lowest.
1 Command line argument
2 Environment variable GRASS_GUI
3 Value set in $HOME/.grass7/rc (GUI)
4 Default value - gui
Python Environment Variables
If you choose to use wxGUI interface, then the GRASS_PYTHON environment variable can be used to override
your system default python command.
Suppose for example your system has Python 3.6 installed and you install a personal version of the Python
3.7 binaries under $HOME/bin. You can use the above variables to have GRASS use the Python 3.7 binaries
instead.
GRASS_PYTHON=python3.7
Addon Path to Extra User Scripts
This environment variable allows the user to extend the GRASS program search paths to include locally
developed/installed GRASS modules or user scripts.
GRASS_ADDON_PATH=/usr/mytools
GRASS_ADDON_PATH=/usr/mytools:/usr/local/othertools
In this example above path(s) would be added to the standard GRASS path environment.
Addon Base for Extra Local GRASS Addon Modules
This environment variable allows the user to extend the GRASS program search paths to include locally
installed (see g.extension for details) GRASS Addon modules which are not distributed with the standard
GRASS release.
GRASS_ADDON_BASE=/usr/grass-addons
In this example above path would be added to the standard GRASS path environment.
If not defined by user, this variable is set by GRASS startup program to $HOME/.grass7/addons on
GNU/Linux and $APPDATA\GRASS7\addons on MS Windows.
HTML Browser Variable
The GRASS_HTML_BROWSER environment variable allows the user to set the HTML web browser to use for
displaying help pages.
Running non-interactive batch jobs
If the GRASS_BATCH_JOB environment variable is set to the full path and filename of a shell script then
GRASS will be launched in a non-interactive way and the script will be run. The script itself can be
interactive if that is what the user requires. When it is finished GRASS will automatically exit using
the exit-success code given by the script. The script file must have its executable bit set.
EXAMPLES
The following are some examples of how you could start GRASS
grass78
Start GRASS using the default user interface. The user will be prompted to choose the appropriate
location and mapset.
grass78 --gui
Start GRASS using the graphical user interface. The user will be prompted to choose the appropriate
location and mapset.
grass78 --text
Start GRASS using the text-based user interface. Appropriate location and mapset must be set by
environmental variables (see examples below) otherwise taken from the last GRASS session.
grass78 --gtext
Start GRASS using the text-based user interface. The user will be prompted to choose the appropriate
location and mapset.
grass78 $HOME/grassdata/spearfish70/user1
Start GRASS using the default user interface and automatically launch into the given mapset,
bypassing the mapset selection menu.
grass78 --gui -
Start GRASS using the graphical user interface and try to obtain the location and mapset from
environment variables.
grass78 -c EPSG:4326 $HOME/grassdata/mylocation
Creates a new GRASS location with EPSG code 4326 (latitude-longitude, WGS84) in the specified
GISDBASE
grass78 -c EPSG:5514:3 $HOME/grassdata/mylocation
Creates a new GRASS location with EPSG code 5514 (S-JTSK / Krovak East North - SJTSK) with datum
transformation parameters used in Czech Republic in the specified GISDBASE
grass78 -c XY $HOME/grassdata/gnomonic --exec g.proj -c proj4=’+proj=gnom +lat_0=90 +lon_0=-50’
Creates a new GRASS location from PROJ definition string (here: gnomonic) in the specified GISDBASE
grass78 -c myvector.shp $HOME/grassdata/mylocation
Creates a new GRASS location based on georeferenced Shapefile
grass78 -c myraster.tif $HOME/grassdata/mylocation
Creates a new GRASS location based on georeferenced GeoTIFF file
Batch jobs with the exec interface
Creating a new Location based on a geodata file’s projection (-c) and exit (-e) immediately:
grass78 -c elevation.tiff -e /path/to/grassdata/test1/
Linking external raster data to PERMANENT Mapset:
grass78 /path/to/grassdata/test1/PERMANENT/ --exec r.external input=basins.tiff output=basins
grass78 /path/to/grassdata/test1/PERMANENT/ --exec r.external input=elevation.tiff output=elevation
Get statistics for one raster map:
grass78 /path/to/grassdata/test1/PERMANENT/ --exec r.univar map=elevation
Compare the rasters visually:
grass78 /path/to/grassdata/test1/PERMANENT/ --exec g.gui.mapswipe first=elevation second=basins
Execution of shell and Python scripts instead of single commands
A sequence of commands can be bundled in a script and executed using the exec interface.
Shell script example: the command to execute a shell script might be:
grass78 /path/to/grassdata/test1/PERMANENT/ --exec sh test.sh
A very simple bash script ("test.sh") may look like this:
#!/bin/bash
g.region -p
g.list type=raster
r.info elevation
Python script example: the command to execute a Python script might be:
grass78 /path/to/grassdata/test1/PERMANENT/ --exec python test.py
A very simple Python script ("test.py") may look like this:
#!/usr/bin/env python3
# import GRASS Python bindings (see also pygrass)
import grass.script as gscript
import grass.script.setup as gsetup
gscript.message(’Current GRASS GIS 7 environment:’)
print(gscript.gisenv())
gscript.message(’Available raster maps:’)
for raster in gscript.list_strings(type=’raster’):
print(raster)
gscript.message(’Available vector maps:’)
for vector in gscript.list_strings(type=’vector’):
print(vector)
Using temporary location
Creating a new temporary location based on a georeferenced file’s projection coordinate reference system
(CRS) and simultaneously starting computation in a shell script:
grass78 --tmp-location elevation.tiff --exec test.sh
The same, but using an EPSG code and a Python script:
grass78 --tmp-location EPSG:3358 --exec test.py
Finally, for special cases, we can create an XY location without any CRS:
grass78 --tmp-location XY --exec test.py
Temporary location is automatically deleted after computation, so the script is expected to export, link
or otherwise preserve the output data before ending.
A single command can be also executed, e.g. to examine properties of the temporary location:
grass78 --tmp-location EPSG:3358 --exec g.proj -p
A temporary XY location with single command is useful, e.g. to show help text of a module:
grass78 --tmp-location XY --exec r.neighbors --help
Troubleshooting
Importantly, to avoid an "[Errno 8] Exec format error" there must be a shebang line at the top of the
script (like #!/bin/sh, #!/bin/bash, or #!/usr/bin/env python3) indicating which interpreter to be used
for the script. The script file must have its executable bit set.
CAVEAT
If you start GRASS using the wxGUI interface you must have a python command in your $PATH variable. That
is, the command must be named python and not something like python3.6. Rarely some Python installations
do not create a python command. In these cases you can override python by GRASS_PYTHON environmental
variable.
Furthermore, if you have more than one version of Python installed, make sure that the version you want
to use with GRASS is set by GRASS_PYTHON environmental variable.
SEE ALSO
List of GRASS environment variables
GRASS GIS Web site
GRASS GIS User Wiki
GRASS GIS Bug Tracker
GRASS GIS 7 Programmer’s Manual
AUTHORS (of this page)
Justin Hickey
Markus Neteler
Hamish Bowman
Martin Landa, Czech Technical University in Prague, Czech Republic
Main index | Topics index | Keywords index | Graphical index | Full index
© 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual