1grass(1) GRASS GIS User's Manual grass(1)
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7 grass [-h | -help | --help] [-v | --version] | [-c | -c geofile | -c
8 EPSG:code[:datum_trans]] | -e | -f | [--text | --gtext | --gui] |
9 --config | [--tmp-location | --tmp-mapset] [[[<GISDBASE>/]<LOCATION>/]
10 <MAPSET>] [--exec EXECUTABLE]
11 Flags:
13 -h | -help | --help
14 Prints a brief usage message and exits
15 -v | --version
17 Prints the version of GRASS and exits
18 -c
20 Creates new GRASS unprojected location in specified GISDBASE
21 -c geofile
23 Creates new GRASS projected location in specified GISDBASE based on
24 georeferenced file
25 -c EPSG:code
27 Creates new GRASS projected location in specified GISDBASE with
28 given EPSG code
29 -c EPSG:code:datum_trans
31 Creates new GRASS projected location in specified GISDBASE with
32 given EPSG code and datum transform parameters
33 -e
35 Exit after creation of location or mapset. Only with -c flag
36 -f
38 Forces removal of .gislock if exists (use with care!). Only with
39 --text flag
40 --text
42 Indicates that Text-based User Interface should be used (skip wel‐
43 come screen)
44 --gtext
46 Indicates that Text-based User Interface should be used (show wel‐
47 come screen)
48 --gui
50 Indicates that Graphical User Interface (wxGUI) should be used
51 --config
53 Prints GRASS configuration parameters (options: arch, build, com‐
54 piler, date, path, python_path, revision, svn_revision, version)
55 --exec EXECUTABLE
57 Execute GRASS module or script. The provided executable will be ex‐
58 ecuted in a GRASS GIS non-interactive session.
59 --tmp-location
61 Run using a temporary location which is created based on the given
62 coordinate reference system and deleted at the end of the execution
63 (use with the --exec flag). The active mapset will be the PERMA‐
64 NENT mapset.
65 --tmp-mapset
67 Run using a temporary mapset which is created in the specified lo‐
68 cation and deleted at the end of the execution (use with the --exec
69 flag).
70 Parameters:
72 GISDBASE
73 Initial database directory which should be a fully qualified path
74 (e.g., /usr/local/share/grassdata)
75 LOCATION
77 Initial location directory which is a subdirectory of GISDBASE
78 MAPSET
80 Initial mapset directory which is a subdirectory of LOCATION Note:
81 These parameters must be specified in one of the following ways:
82 MAPSET
83 LOCATION/MAPSET
84 GISDBASE/LOCATION/MAPSET
85
87 This command is used to launch GRASS GIS. It will parse the command
88 line arguments and then initialize GRASS for the user. Since GRASS mod‐
89 ules require a specific environment, this program must be called before
90 any other GRASS module can run. The command line arguments are optional
91 and provide the user with a method to indicate the desired user inter‐
92 face, as well as the desired mapset to work on.
93 The startup program will remember both the desired user interface and
95 mapset. Thus, the next time the user runs GRASS, typing grass (without
96 any options) will start GRASS with the previous settings for the user
97 interface and mapset selected.
98 If you specify a graphical user interface (--gui) the grass program
100 will try to verify that the system you specified exists and that you
101 can access it successfully. If any of these checks fail then grass will
102 automatically switch back to the text user interface mode.
103 Running non-interactive jobs
105 The --exec flag can run an executable on path, GRASS module, or a
106 script. All are executed as a subprocess and any additional arguments
107 are passed to it. A script needs to be specified by full or relative
108 path and on unix-likes systems, the script file must have its exe‐
109 cutable bit set. Calling the interpreter (e.g., python) and providing
110 the script as a parameter is possible, too. When it is finished GRASS
111 will automatically exit using the return code given by the subprocess.
112 Although the execution itself is non-interactive (no GUI or shell), the
113 subprocess itself can be interactive if that is what the user requires.
114 Config flag
116 The flag --config option prints GRASS GIS configuration and version pa‐
117 rameters, with the options:
118 • arch: system architecture (e.g., x86_64-pc-linux-gnu)
120 • build: (e.g., ./configure --with-cxx --enable-largefile
122 --with-proj [...])
123 • compiler: (e.g., gcc)
125 • date: (e.g., Tue Mar 31 20:34:57 2020 +0200)
127 • path: (e.g., /usr/lib64/grass)
129 • python_path: (e.g., /usr/lib64/grass/etc/python)
131 • revision: (e.g., 745ee7ec9)
133 • svn_revision: (e.g., 062bffc8)
135 • version: (e.g., 8.2.0dev)
137
139 The GRASS GIS project provides several free sample geospatial datasets
140 as ready-to-use locations. They are available to download at
141 https://grass.osgeo.org/download/sample-data/. The "North Carolina
142 data set" is a modern package of geospatial data from North Carolina
143 (USA), and it includes raster, vector, LiDAR and satellite data. This
144 is the most extensively used data set in the documentation and the ex‐
145 amples throughout the user manual pages are based upon it.
146
148 A number of environment variables are available at GRASS startup to as‐
149 sist with automation and customization. Most users will not need to
150 bother with these.
151 In addition to these shell environment variables GRASS maintains a num‐
153 ber of GIS environment variables in the $HOME/.grass8/rc file. User
154 changes to this file will be read during the next startup of GRASS. If
155 this file becomes corrupted the user may edit it by hand or remove it
156 to start afresh. See the list of implemented GRASS variables for more
157 information. The rest of this help page will only consider shell envi‐
158 ronment variables.
159 Note that you will need to set these variables using the appropriate
161 method required for the UNIX shell that you use (e.g. in a Bash shell
162 you must export the variables for them to propagate).
163 User Interface Environment Variable
165 The grass program will check for the existence of an environment vari‐
166 able called GRASS_GUI which indicates the type of user interface for
167 GRASS to use. If this variable is not set when grass is run, then it
168 will be created and then saved in the $HOME/.grass8/rc file for the
169 next time GRASS is run. It can be set to text, gtext or gui.
170 There is an order of precedence in the way grass determines the user
172 interface to use. The following is the hierarchy from highest prece‐
173 dence to lowest.
174 1 Command line argument
176 2 Environment variable GRASS_GUI
178 3 Value set in $HOME/.grass8/rc (GUI)
180 4 Default value - gui
182 Python Environment Variables
184 If you choose to use wxGUI interface, then the GRASS_PYTHON environment
185 variable can be used to override your system default python command.
186 Suppose for example your system has Python 3.6 installed and you in‐
188 stall a personal version of the Python 3.8 binaries under $HOME/bin.
189 You can use the above variables to have GRASS use the Python 3.8 bina‐
190 ries instead.
191 GRASS_PYTHON=python3.8
192 Addon Path to Extra User Scripts
194 This environment variable allows the user to extend the GRASS program
195 search paths to include locally developed/installed GRASS modules or
196 user scripts.
197 GRASS_ADDON_PATH=/usr/mytools
198 GRASS_ADDON_PATH=/usr/mytools:/usr/local/othertools
199 In this example above path(s) would be added to the standard GRASS path
201 environment.
202 Addon Base for Extra Local GRASS Addon Modules
204 This environment variable allows the user to extend the GRASS program
205 search paths to include locally installed (see g.extension for details)
206 GRASS Addon modules which are not distributed with the standard GRASS
207 release.
208 GRASS_ADDON_BASE=/usr/grass-addons
209 In this example above path would be added to the standard GRASS path
211 environment.
212 If not defined by user, this variable is set by GRASS startup program
214 to $HOME/.grass8/addons on GNU/Linux and %APPDATA%\Roaming\GRASS8\ad‐
215 dons on MS Windows.
216 HTML Browser Variable
218 The GRASS_HTML_BROWSER environment variable allows the user to set the
219 HTML web browser to use for displaying help pages.
220
222 The following are some examples of how you could start GRASS
223 grass
225 Start GRASS using the default user interface. The user will be
226 prompted to choose the appropriate location and mapset.
227 grass --gui
229 Start GRASS using the graphical user interface. The user will be
230 prompted to choose the appropriate location and mapset.
231 grass --text
233 Start GRASS using the text-based user interface. Appropriate loca‐
234 tion and mapset must be set by environmental variables (see exam‐
235 ples below) otherwise taken from the last GRASS session.
236 grass --gtext
238 Start GRASS using the text-based user interface. The user will be
239 prompted to choose the appropriate location and mapset.
240 grass $HOME/grassdata/spearfish70/user1
242 Start GRASS using the default user interface and automatically
243 launch into the given mapset, bypassing the mapset selection menu.
244 grass --gui -
246 Start GRASS using the graphical user interface and try to obtain
247 the location and mapset from environment variables.
248 grass -c EPSG:4326 $HOME/grassdata/mylocation
250 Creates a new GRASS location with EPSG code 4326 (latitude-longi‐
251 tude, WGS84) in the specified GISDBASE
252 grass -c EPSG:5514:3 $HOME/grassdata/mylocation
254 Creates a new GRASS location with EPSG code 5514 (S-JTSK / Krovak
255 East North - SJTSK) with datum transformation parameters used in
256 Czech Republic in the specified GISDBASE
257 grass -c XY $HOME/grassdata/gnomonic --exec g.proj -c proj4=’+proj=gnom
259 +lat_0=90 +lon_0=-50’
260 Creates a new GRASS location from PROJ definition string (here:
261 gnomonic) in the specified GISDBASE
262 grass -c myvector.shp $HOME/grassdata/mylocation
264 Creates a new GRASS location based on georeferenced Shapefile
265 grass -c myraster.tif $HOME/grassdata/mylocation
267 Creates a new GRASS location based on georeferenced GeoTIFF file
268 Batch jobs with the exec interface
270 Creating a new Location based on a geodata file’s projection (-c) and
271 exit (-e) immediately:
272 grass -c elevation.tiff -e /path/to/grassdata/test1/
273 Linking external raster data to PERMANENT Mapset:
274 grass /path/to/grassdata/test1/PERMANENT/ --exec r.external input=basins.tiff output=basins
275 grass /path/to/grassdata/test1/PERMANENT/ --exec r.external input=elevation.tiff output=elevation
276 Get statistics for one raster map:
277 grass /path/to/grassdata/test1/PERMANENT/ --exec r.univar map=elevation
278 Compare the rasters visually:
279 grass /path/to/grassdata/test1/PERMANENT/ --exec g.gui.mapswipe first=elevation second=basins
280 Execution of shell and Python scripts instead of single commands
282 A sequence of commands can be bundled in a script and executed using
283 the exec interface.
284 Shell script example: the command to execute a shell script might be:
286 grass /path/to/grassdata/test1/PERMANENT/ --exec sh test.sh
287 A very simple bash script ("test.sh") may look like this:
288 #!/bin/bash
289 g.region -p
290 g.list type=raster
291 r.info elevation
292 Python script example: the command to execute a Python script might be:
294 grass /path/to/grassdata/test1/PERMANENT/ --exec python test.py
295 A very simple Python script ("test.py") may look like this:
296 #!/usr/bin/env python3
297 # import GRASS Python bindings (see also pygrass)
298 import grass.script as gs
299 import grass.script.setup as gsetup
300 gs.message(’Current GRASS GIS 8 environment:’)
301 print(gs.gisenv())
302 gs.message(’Available raster maps:’)
303 for raster in gs.list_strings(type=’raster’):
304 print(raster)
305 gs.message(’Available vector maps:’)
306 for vector in gs.list_strings(type=’vector’):
307 print(vector)
308 Using temporary location
310 Creating a new temporary location based on a georeferenced file’s pro‐
311 jection coordinate reference system (CRS) and simultaneously starting
312 computation in a shell script:
313 grass --tmp-location elevation.tiff --exec test.sh
314 The same, but using an EPSG code and a Python script:
315 grass --tmp-location EPSG:3358 --exec test.py
316 Finally, for special cases, we can create an XY location without any
317 CRS:
318 grass --tmp-location XY --exec test.py
319 Temporary location is automatically deleted after computation, so the
320 script is expected to export, link or otherwise preserve the output
321 data before ending.
322 A single command can be also executed, e.g. to examine properties of
324 the temporary location:
325 grass --tmp-location EPSG:3358 --exec g.proj -p
326 A temporary XY location with single command is useful, e.g. to show
327 help text of a module:
328 grass --tmp-location XY --exec r.neighbors --help
329 Using temporary mapset
331 A single command can be executed, e.g., to examine properties of a lo‐
332 cation (here using the NC SPM sample location):
333 grass --tmp-mapset /path/to/grassdata/nc_spm_08/ --exec g.proj -p
334 Computation in a Python script can be executed in the same way:
335 grass --tmp-mapset /path/to/grassdata/nc_spm_08/ --exec processing.py
336 Additional parameters are just passed to the script, so we can run the
337 script with different sets of parameters (here 5, 8 and 3, 9) in dif‐
338 ferent temporary mapsets which is good for parallel processing.
339 grass --tmp-mapset /path/to/grassdata/nc_spm_08/ --exec processing.py 5 8
340 grass --tmp-mapset /path/to/grassdata/nc_spm_08/ --exec processing.py 3 9
341 The same applies to Bash scripts (and other scripts supported on you
342 platform):
343 grass --tmp-mapset /path/to/grassdata/nc_spm_08/ --exec processing.sh 5 8
344 The temporary mapset is automatically deleted after computation, so the
345 script is expected to export, link or otherwise preserve the output
346 data before ending.
347 Troubleshooting
349 Importantly, to avoid an "[Errno 8] Exec format error" there must be a
350 shebang line at the top of the script (like #!/bin/sh, #!/bin/bash, or
351 #!/usr/bin/env python3) indicating which interpreter to be used for the
352 script. The script file must have its executable bit set.
353
355 If you start GRASS using the wxGUI interface you must have a python
356 command in your $PATH variable. That is, the command must be named
357 python and not something like python3.6. Rarely some Python installa‐
358 tions do not create a python command. In these cases you can override
359 python by GRASS_PYTHON environmental variable.
360 Furthermore, if you have more than one version of Python installed,
362 make sure that the version you want to use with GRASS is set by
363 GRASS_PYTHON environmental variable.
364
366 List of GRASS environment variables
367 GRASS GIS Web site
369 GRASS GIS User Wiki
370 GRASS GIS Bug Tracker
371 GRASS GIS 8 Programmer’s Manual
372
374 Justin Hickey
375 Markus Neteler
376 Hamish Bowman
377 Martin Landa, Czech Technical University in Prague, Czech Republic
378 Main index | Topics index | Keywords index | Graphical index | Full in‐
380 dex
381 © 2003-2023 GRASS Development Team, GRASS GIS 8.2.1 Reference Manual
383GRASS 8.2.1 grass(1)