v.what.1grass - Man Page
Queries a vector map at given locations.
Keywords
vector, querying, position
Synopsis
v.what
v.what --help
v.what [-aidgjm] map=name[,name,...] [layer=string[,string,...]] [type=string[,string,...]] coordinates=east,north [distance=float] [columns=name[,name,...]] [format=name] [--help] [--verbose] [--quiet] [--ui]
Flags
- -a
Print attribute information
- -i
Print attribute database connection information
- -d
Print topological information (debugging)
Prints internal information for topology debugging- -g
Print the stats in shell script style [deprecated]
This flag is deprecated and will be removed in a future release. Use format=shell instead.- -j
Print the stats in JSON [deprecated]
This flag is deprecated and will be removed in a future release. Use format=json instead.- -m
Print multiple features for each map if they meet the criteria
For JSON, this places features under a "features" key- --help
Print usage summary
- --verbose
Verbose module output
- --quiet
Quiet module output
- --ui
Force launching GUI dialog
Parameters
- map=name[,name,...]Â [required]
Name of vector map(s)
- layer=string[,string,...]
Layer number or name (’-1’ for all layers)
A single vector map can be connected to multiple database tables. This number determines which table to use. When used with direct OGR access this is the layer name.
Default: -1- type=string[,string,...]
Input feature type
Options: point, line, boundary, centroid, area, face, kernel
Default: point,line,area,face- coordinates=east,north [required]
Coordinates for query
’-’ for standard input- distance=float
Query threshold distance
Default: 0- columns=name[,name,...]
Name of attribute column(s)
Default: all columns- format=name
Output format
Options: plain, shell, json
plain: Plain text output
shell: shell script style output
json: JSON (JavaScript Object Notation)
Description
v.what outputs the category number value(s) associated with user-specified location(s) in user-specified vector map layer(s). This module was derived from the d.what.vect module by removing all interactive code and modification of the output for easy parsing. Using the -g flag generates script-style output which is easily parsable.
Example
North Carolina sample dataset example:
Query polygon at given position:
v.what zipcodes_wake coordinates=637502.25,221744.25
Find closest hospital to given position within given distance (search radius):
v.what hospitals coordinates=542690.4,204802.7 distance=2000000
See Also
d.what.rast, d.what.vect, v.rast.stats, v.vect.stats, v.what.rast, v.what.rast3, v.what.vect
Author
Trevor Wiens
Edmonton, Alberta, Canada
Source Code
Available at: v.what source code (history)
Latest change: Sunday Oct 19 06:41:19 2025 in commit: 3852c52a6ee5ed16ab7c0d2129951ff2d4badb8b
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