v.info
Outputs basic information about a vector map.
v.info [-chegt] map=name [layer=string] [format=name] [--verbose] [--quiet] [--qq] [--ui]
Example:
v.info map=name
grass.script.parse_command("v.info", map, layer="1", format=None, flags=None, verbose=False, quiet=False, superquiet=False)
Example:
gs.parse_command("v.info", map="name", format="json")
Parameters
map=name [required]
Name of vector map
Or data source for direct OGR access
layer=string
Layer number or name
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Default: 1
format=name
Output format
Allowed values: plain, shell, json
plain: Human readable text output
shell: shell script style text output
json: JSON (JavaScript Object Notation)
-c
Print attribute table columns instead of info
Column names and types are printed for the specified layer if it has an attribute table database connection
-h
Print data history instead of info
-e
Print only metadata info
-g
Print only region info
-t
Print only topology info
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--qq
Very quiet module output
--ui
Force launching GUI dialog
map : str, required
Name of vector map
Or data source for direct OGR access
Used as: input, vector, name
layer : str, optional
Layer number or name
Vector features can have category values in different layers. This number determines which layer to use. When used with direct OGR access this is the layer name.
Used as: input, layer
Default: 1
format : str, optional
Output format
Used as: name
Allowed values: plain, shell, json
plain: Human readable text output
shell: shell script style text output
json: JSON (JavaScript Object Notation)
flags : str, optional
Allowed values: c, h, e, g, t
c
Print attribute table columns instead of info
Column names and types are printed for the specified layer if it has an attribute table database connection
h
Print data history instead of info
e
Print only metadata info
g
Print only region info
t
Print only topology info
verbose: bool, optional
Verbose module output
Default: False
quiet: bool, optional
Quiet module output
Default: False
superquiet: bool, optional
Very quiet module output
Default: False
DESCRIPTION
The v.info tool reports basic information about a vector map, including its topology status.
When the attribute database connection is defined, the
information about it is included in the JSON and shell outputs.
If the connection is not defined for the given layer,
no fields related to attribute database are included in the output
except num_dblinks. To work with multiple layers within one vector map or
attribute tables connected to other layer than the first layer,
use v.info together with the v.db.connect tool.
If the vector map is connected to one or more attribute tables, the -c flag can be used to obtain the names and types of the attribute columns. The columns are always printed for the attribute table linked to the layer specified as a parameter. If the given layer is not connected to attribute table database, the tools produces and error. The current attribute database connections can be displayed or configured using v.db.connect.
If the topology information is unavailable (i.e., the vector map cannot be opened at level 2), the spatial extent and number of features must be calculated on the fly, which may take some time with large amounts of data.
Flags -g, -e, -t can be used to retrieve only a subset of information. Use one or more of these flags together with the format set to "json" or "shell". For example, you can retrieve non-spatial metadata with the -g flag without calculating the spatial extent and number of features when they are unavailable (see above). Providing all three of these flags is the same as not providing any.
NOTES
For backwards compatibility reasons, using flags -g, -e, -t, -c, -h without format, automatically switches to the shell format. In the next major release, this may be changed to keep the plain format output to best serve interactive use. Specify format shell or json explicitly for scripting.
For history (-h flag), always use JSON output (format="json").
Do not rely on parsing the shell format output which is currently
fully dependent on the internal storage format. In the next major release, the
shell format may be changed dramatically.
EXAMPLES
Metadata information
Get all the basic information such as title and topology information:
v.info map=geology
Possible output:
+----------------------------------------------------------------------------+
| Name: geology |
| Mapset: PERMANENT |
| Project: nc_spm_08 |
| Database: /home/martin/grassdata |
| Title: North Carolina geology map (polygon map) |
| Map scale: 1:1 |
| Map format: native |
| Name of creator: helena |
| Organization: NC OneMap |
| Source date: Mon Nov 6 15:48:53 2006 |
|----------------------------------------------------------------------------|
| Type of map: vector (level: 2) |
| |
| Number of points: 0 Number of centroids: 1832 |
| Number of lines: 0 Number of boundaries: 3649 |
| Number of areas: 1832 Number of islands: 907 |
| |
| Map is 3D: No |
| Number of dblinks: 1 |
| |
| Projection: Lambert Conformal Conic |
| |
| N: 318117.43741634 S: 10875.82723209 |
| E: 930172.31282271 W: 123971.19498978 |
| |
| Digitization threshold: 0 |
| Comment: |
| |
+----------------------------------------------------------------------------+
import grass.script as gs
data = gs.parse_command("v.info", map="geology", format="json")
print(data["title"])
Possible output:
North Carolina hospitals (points map)
The whole JSON may look like this:
{
"name": "geology",
"mapset": "PERMANENT",
"project": "nc_spm_08",
"database": "\/home\/martin\/grassdata",
"title": "North Carolina geology map (polygon map)",
"scale": "1:1",
"creator": "helena",
"organization": "NC OneMap",
"source_date": "Mon Nov 6 15:48:53 2006",
"timestamp": null,
"format": "native",
"level": 2,
"num_dblinks": 1,
"attribute_layer_number": 1,
"attribute_layer_name": "geology",
"attribute_database": "\/home\/martin\/grassdata\/nc_spm_08\/PERMANENT\/sqlite\/sqlite.db",
"attribute_database_driver": "sqlite",
"attribute_table": "geology",
"attribute_primary_key": "cat",
"projection": "Lambert Conformal Conic",
"digitization_threshold": 0,
"comment": "",
"north": 318117.43741634465,
"south": 10875.827232091688,
"east": 930172.31282271142,
"west": 123971.19498978264,
"top": 0,
"bottom": 0,
"nodes": 2724,
"points": 0,
"lines": 0,
"boundaries": 3649,
"centroids": 1832,
"areas": 1832,
"islands": 907,
"primitives": 5481,
"map3d": false
}
Attribute table columns
The tool returns attribute column for a specified layer within the vector map. The default layer is layer 1 which is usually the one connected to an attribute table database, so leaving the default value produces the expected result:
v.info -c map=geology format=shell
Possible output:
INTEGER|cat
DOUBLE PRECISION|onemap_pro
DOUBLE PRECISION|PERIMETER
INTEGER|GEOL250_
INTEGER|GEOL250_ID
CHARACTER|GEO_NAME
DOUBLE PRECISION|SHAPE_area
DOUBLE PRECISION|SHAPE_len
import grass.script as gs
data = gs.parse_command("v.info", map="geology", flags="c", format="json")
print("names:", ", ".join(column["name"] for column in data["columns"]))
Possible output:
names: cat, onemap_pro, PERIMETER, GEOL250_, GEOL250_ID, GEO_NAME, SHAPE_area, SHAPE_len
Map history
v.info -h map=geology
Possible output:
COMMAND: v.in.ogr input="geol.shp" output="geology" min_area=0.0001 snap=-1
GISDBASE: /bigdata/grassdata05
LOCATION: ncfromfile MAPSET: PERMANENT USER: helena DATE: Mon Nov 6 15:48:53 2006
---------------------------------------------------------------------------------
1832 input polygons
total area: 1.276093e+11 (1832 areas)
overlapping area: 0.000000e+00 (0 areas)
area without category: 0.000000e+00 (0 areas)
---------------------------------------------------------------------------------
Note that while "project" is used by v.info elsewhere, history output uses the legacy term "location" because "LOCATION" is currently a part of the native vector format.
import grass.script as gs
data = gs.parse_command("v.info", map="hospitals", flags="h", format="json")
for record in data["records"]:
print(record["command"])
Possible output:
v.in.ogr dsn="hls.shp" output="hospitals" min_area=0.0001 snap=-1
v.db.connect -o map="hospitals@PERMANENT" driver="sqlite" database="$GISDBASE/$LOCATION_NAME/$MAPSET/sqlite/sqlite.db" table="hospitals" key="cat" layer="1" separator="|"
Limiting the output
v.info -g map=geology
Possible output:
north=318117.43741634
south=10875.82723209
east=930172.31282271
west=123971.19498978
top=0.000000
bottom=0.000000
import grass.script as gs
data = gs.parse_command("v.info", map="geology", flags="g", format="json")
print(data)
Possible output:
{'north': 318117.43741634465, 'south': 10875.827232091688, 'east': 930172.3128227114, 'west': 123971.19498978264, 'top': 0, 'bottom': 0}
SEE ALSO
v.db.connect, v.category, r.info, r3.info, t.info
AUTHORS
Original author CERL
Updated to GRASS 6 by Radim Blazek, ITC-Irst, Trento, Italy
Level 1 support by Markus Metz
Updated to GRASS 7 by Martin Landa, CTU in Prague, Czech Republic
SOURCE CODE
Available at: v.info source code
(history)
Latest change: Friday Jun 20 17:03:48 2025 in commit 2445ad4