NAME
g.gisenv - Outputs and modifies the user's current GRASS variable settings.
Prints all defined GRASS variables if no option is given.
KEYWORDS
general,
settings,
variables,
scripts
SYNOPSIS
g.gisenv
g.gisenv --help
g.gisenv [-sn] [get=variable[,variable,...]] [set="variable=value"] [unset=variable[,variable,...]] [store=string] [separator=character] [--help] [--verbose] [--quiet] [--ui]
Flags:
- -s
- Use shell syntax (for "eval")
- -n
- Do not use shell syntax
- --help
- Print usage summary
- --verbose
- Verbose module output
- --quiet
- Quiet module output
- --ui
- Force launching GUI dialog
Parameters:
- get=variable[,variable,...]
- GRASS variable to get
- set="variable=value"
- GRASS variable to set
- unset=variable[,variable,...]
- GRASS variable to unset
- store=string
- Where GRASS variable is stored
- Options: gisrc, mapset
- Default: gisrc
- separator=character
- Separator for multiple GRASS variables
- Special characters: pipe, comma, space, tab, newline
- Default: newline
When a user runs GRASS, certain variables are set specifying the GRASS
data base, project, mapset, peripheral device drivers, etc., being
used in the current GRASS session. These variable name settings are
recognized as long as the user is running a GRASS session.
No prompts are given to the user when running
g.gisenv.
If run without arguments, g.gisenv lists all of the user's
current GRASS variable settings. Results are sent to standard output,
and may look like this:
GISDBASE=/opt/grassdata/
LOCATION_NAME=nc_spm_08_grass7
MAPSET=/user1
GUI=gui
If the user specifies a get=variable_name on the
command line
only the value for that particular GRASS variable is output to
standard output. Possible variable names depend on the user's system,
see
variables list for details. Note that
the variable names are case-insensitive.
While other variables may be associated with each GRASS session (e.g.,
GRASS_GUI, GIS_LOCK, and other variables), those stated below
are essential.
- GISDBASE
- The GISDBASE is a directory in which all users' GRASS
data are stored. Within the GISDBASE, data are segregated
into subdirectories (called "projects") based on the map
coordinate system used and the geographic extent of the data. Each
"project" directory itself contains subdirectories called
"mapsets"; each "mapset" stores "data base
elements" - the directories (e.g.,
the cell, cellhd, vector, etc., directories)
in which GRASS data files are actually stored.
- LOCATION_NAME
- The user must choose to work with the data under a single GRASS
project (previously called "location") within any given
GRASS session; this project is then called
the current GRASS project, and is specified by the variable
LOCATION_NAME. The LOCATION_NAME is the GRASS data
base location whose data will be affected by any GRASS commands issued
during the user's current GRASS session, and is a subdirectory of the
current GISDBASE. Each "project" directory can
contain multiple "mapset" directories (including the special
mapset PERMANENT). Maps stored under the same
GRASS LOCATION_NAME (and/or within the same MAPSET)
must use the same coordinate system and typically fall within the
boundaries of the same geographic region.
- MAPSET
- Each "mapset" contains a set of maps relevant to the
LOCATION_NAME directory in which it appears.
Each LOCATION_NAME can contain multiple mapsets. (Mapsets
which fall under the same LOCATION_NAME all contain data
geographically relevant to the LOCATION_NAME, and all store
data in the same map coordinate system. Frequently, maps are placed
into different mapsets to distinguish file ownership - e.g., each user
might have one or more own mapset(s), storing any maps that the user has
created and/or are relevant to the own work.) During each GRASS session, the
user must choose one mapset to be the current mapset; the current
mapset setting is given by MAPSET, and is a subdirectory
of LOCATION_NAME. During a single GRASS session, the user
can use available data in any of the mapsets stored under the
current LOCATION_NAME directory that are in the user's
mapset search path and accessible by the user. However, within a
single GRASS session, the user only has write access to data
stored under the current mapset (specified by the
variable MAPSET).
Each "mapset" stores GRASS data base elements (i.e., the
directories in which GRASS data files are stored). Any maps created
or modified by the user in the current GRASS session will be stored
here. The MAPSET directory PERMANENT is generally
reserved for the set of maps that form the base set for all users
working under each LOCATION_NAME.
Once within a GRASS session, GRASS users have access only to the data
under a single GRASS data base directory (the current GRASS data
base, specified by the variable GISDBASE), and to a
single GRASS project directory (the current project,
specified by the variable LOCATION_NAME). Within a single
session, the user may only modify the data in the
current mapset (specified by the variable
MAPSET), but may use data available under other
mapsets under the same LOCATION_NAME.
All of these names must be legal names on the user's current system.
The full path to the current mapset is determined
from GISDBASE, LOCATION_NAME, MAPSET
variables, in the example
above: /opt/grassdata/spearfish/PERMANENT. The full path can
be printed using g.gisenv by providing multiple variables:
g.gisenv get=GISDBASE,LOCATION_NAME,MAPSET sep='/'
/opt/grassdata/nc_spm_08_grass7/user1
The output from
g.gisenv
when invoked without arguments is directly usable by Bash. The
following command will cast each variable into the UNIX environment:
This works only for
Bash,
sh,
ksh, etc. The format of the output is not
compatible with some other UNIX shells.
By default the GRASS variables are stored in gisrc file
(defined by environmental
variable GISRC). If store=mapset is given then the
variables are stored in <gisdbase>/<project>/<mapset>/VAR
after the current GRASS session is closed.
The maximum memory to be used, i.e. the cache size for raster rows, is set
to 300 MB by default (GRASS variable
MEMORYMB). To speed up
raster operations, it is recommended to increase this setting if enough RAM
is available. It is important to note that parallel processes will each
consume this amount of RAM.
Set the maximum memory to be used (in MB), i.e. the cache size for raster rows:
# set to 6 GB (default: 300 MB)
g.gisenv set="MEMORYMB=6000"
Set the number of threads for parallel computing:
# set to use 12 threads (default: 1)
g.gisenv set="NPROCS=12"
To print debugging messages, the variable
DEBUG must be set to level
equal or greater than 0:
Levels: (recommended levels)
- 0 - silence
- 1 - message is printed once or few times per module
- 3 - each row (raster) or line (vector)
- 5 - each cell (raster) or point (vector)
To disable debugging messages:
The variable DEBUG controls debugging messages from GRASS libraries
and modules.
Similarly WX_DEBUG controls debugging messages
from wxGUI.
g.access,
g.filename,
g.findfile,
g.mapsets
See also
list of selected GRASS gisenv variables
Michael Shapiro,
U.S.Army Construction Engineering Research Laboratory
SOURCE CODE
Available at:
g.gisenv source code
(history)
Latest change: Wednesday Nov 27 22:53:26 2024 in commit: 3b5486c0463a7103ab2109e28bf860fe34539868
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© 2003-2024
GRASS Development Team,
GRASS GIS 8.5.0dev Reference Manual