1g.gisenv(1) Grass User's Manual g.gisenv(1)
2
6 g.gisenv - Outputs and modifies the user's current GRASS variable set‐
7 tings.
8
10 general
11
13 g.gisenv
14 g.gisenv help
15 g.gisenv [get=VARIABLE] [set="VARIABLE=value"] [store=string]
16 [--verbose] [--quiet]
17 Parameters:
19 get=VARIABLE
20 GRASS variable to get
21 set=
23 GRASS variable to set
24 store=string
26 Where GRASS variable is stored
27 Options: gisrc,mapset
28 Default: gisrc
29
31 When a user runs GRASS, certain variables are set specifying the GRASS
32 data base, location, mapset, peripheral device drivers, etc., being
33 used in the current GRASS session. These variable name settings are
34 recognized as long as the user is running a GRASS session.
35
37 No prompts are given to the user when running g.gisenv. If run without
38 arguments, g.gisenv lists all of the user's current GRASS variable set‐
39 tings. Results are sent to standard output, and may look like this:
40 GISDBASE=/usr/grass5/data
41 LOCATION_NAME=spearfish
42 MAPSET=PERMANENT
43 In this example, the full path name of the user's current location
44 (i.e., $LOCATION_NAME) is /usr/grass5/data/spearfish, and the full path
45 name of the user's current mapset (i.e., $MAPSET) is
46 /usr/grass5/data/spearfish/PERMANENT.
47 If the user specifies a variable_name on the command line (e.g.,
49 g.gisenv MAPSET), only the value for that particular GRASS variable is
50 output to standard output. Possible variable names depend on the
51 user's system, see variables list for details.
52 While other variables may be associated with each GRASS session (e.g.,
54 DIGITIZER, PAINTER, DISPLAY, and other variables), those stated below
55 are essential.
56 GISDBASE
58 The $GISDBASE is a directory in which all users' GRASS data are
59 stored. Within the $GISDBASE, data are segregated into subdi‐
60 rectories (called "locations") based on the map coordinate sys‐
61 tem used and the geographic extent of the data. Each "location"
62 directory itself contains subdirectories called "mapsets"; each
63 "mapset" stores "data base elements" -- the directories (e.g.,
64 the cell, cellhd, dig, etc., directories) in which GRASS data
65 files are actually stored.
66 LOCATION_NAME
68 The user must choose to work with the data under a single GRASS
69 location within any given GRASS session; this location is then
70 called the current GRASS location, and is specified by the vari‐
71 able $LOCATION_NAME. The $LOCATION_NAME is the GRASS data base
72 location whose data will be affected by any GRASS commands
73 issued during the user's current GRASS session, and is a subdi‐
74 rectory of the current $GISDBASE. Each "location" directory can
75 contain multiple "mapset" directories (including the special
76 mapset PERMANENT). Maps stored under the same GRASS LOCA‐
77 TION_NAME (and/or within the same MAPSET) must use the same
78 coordinate system and typically fall within the boundaries of
79 the same geographic region (aka, "location").
80 MAPSET
82 Each "mapset" contains a set of maps relevant to the LOCA‐
83 TION_NAME directory in which it appears. Each LOCATION_NAME can
84 contain multiple mapsets. (Mapsets which fall under the same
85 LOCATION_NAME all contain data geographically relevant to the
86 LOCATION_NAME, and all store data in the same map coordinate
87 system. Frequently, maps are placed into different mapsets to
88 distinguish file ownership -- e.g., each user might have his own
89 mapset, storing any maps that he has created and/or are relevant
90 to his work.) During each GRASS session, the user must choose
91 one mapset to be the current mapset; the current mapset setting
92 is given by $MAPSET, and is a subdirectory of $LOCATION_NAME.
93 During a single GRASS session, the user can use available data
94 in any of the mapsets stored under the current LOCATION_NAME
95 directory that are in the user's mapset search path and accessi‐
96 ble by the user. However, within a single GRASS session, the
97 user only has write access to data stored under the current
98 mapset (specified by the variable $MAPSET).
99 Each "mapset" stores GRASS data base elements (i.e., the directories in
101 which GRASS data files are stored). Any maps created or modified by
102 the user in the current GRASS session will be stored here. The MAPSET
103 directory PERMANENT is generally reserved for the set of maps that form
104 the base set for all users working under each LOCATION_NAME.
105 Once within a GRASS session, GRASS users have access only to the data
107 under a single GRASS data base directory (the current GRASS data base,
108 specified by the variable $GISDBASE), and to a single GRASS location
109 directory (the current location, specified by the variable $LOCA‐
110 TION_NAME). Within a single session, the user may only modify the data
111 in the current mapset (specified by the variable $MAPSET), but may use
112 data available under other mapsets under the same LOCATION_NAME.
113 All of these names must be legal names on the user's current system.
115 For UNIX users, names less than 14 characters and containing no non-
116 printing or space codes are permissible. Examples of permissible names
117 include: one, mymap, VeGe_map, and 1_for_me. The underscore character
118 can safely be used in place of a blank for multiple-word names.
119
121 The output from g.gisenv when invoked without arguments is directly
122 usable by /bin/sh. The following command will cast each variable into
123 the UNIX environment:
124 eval `g.gisenv`
127 This works only for /bin/sh. The format of the output is not compatible
130 with other UNIX shells.
131 GRASS Debugging:
133 To print debugging messages, the variable DEBUG must be set to level
134 equal or greater than 0:
135 <TT>g.gisenv set="DEBUG=3"
138 Levels: (recommended levels)
141 0 - silence
143 1 - message is printed once or few times per module
145 3 - each row (raster) or line (vector)
147 5 - each cell (raster) or point (vector)
149 To disable debugging messages, DEBUG must be set back to 0:
150 <TT>g.gisenv set="DEBUG=0"
153
156 g.access
157 g.ask
158 g.filename
159 g.findfile
160 g.mapsets
161 variables list
162
164 Michael Shapiro, U.S.Army Construction Engineering Research Laboratory
165 Last changed: $Date: 2005-12-07 14:31:16 +0100 (Wed, 07 Dec 2005) $
167 Full index
169 © 2003-2008 GRASS Development Team
171GRASS 6.3.0 g.gisenv(1)