This is the command g.extensiongrass that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator
g.extension - Maintains GRASS Addons extensions in local GRASS installation.
Downloads, installs extensions from GRASS Addons SVN repository into local GRASS
installation or removes installed extensions.
general, installation, extensions
g.extension [-lcgasdift] extension=name operation=string [svnurl=url] [prefix=path]
[proxy=proxy[,proxy,...]] [--help] [--verbose] [--quiet] [--ui]
List available extensions in the GRASS Addons SVN repository
List available extensions in the GRASS Addons SVN repository including module
List available extensions in the GRASS Addons SVN repository (shell script style)
List locally installed extensions
Install system-wide (may need system administrator rights)
Download source code and exit
Do not install new extension, just compile it
Force removal when uninstalling extension (operation=remove)
Operate on toolboxes instead of single modules (experimental)
Print usage summary
Verbose module output
Quiet module output
Force launching GUI dialog
Name of extension to install or remove
Name of toolbox (set of extensions) when -t flag is given
Operation to be performed
Options: add, remove
SVN Addons repository URL
Prefix where to install extension (ignored when flag -s is given)
Set the proxy with: "http=<value>,ftp=<value>"
g.extension downloads and installs, removes or updates extensions (addons) from the
official GRASS GIS Addons repository or user-specified source into the local GRASS GIS
Two types of extensions are supported:
· Python scripts: they are installed without the need of compilation or (usually)
the need of special dependencies.
· Source code (mostly written in C programming language; may also be written in C++,
Fortran or other languages): while on MS-Windows systems the requested GRASS GIS
extension is downloaded pre-compiled from the GRASS GIS site, on Unix based
systems the installation is preceded by the automated download of the extension’s
source code along with subsequent compilation and installation. This requires a
compiler environment to be present on the user’s computer.
Managing installed extensions
Re-running g.extension on an installed GRASS GIS Addon extension re-installs the requested
extension which may include updates.
To bulk-update all locally installed GRASS GIS extensions, g.extension.all module is
Where the extensions are installed
GRASS GIS extensions are installed by g.extension into a dedicated directory. The default
is a directory for application data and settings inside the user’s home directory. On
GNU/Linux it is $HOME/.grass7/addons, on MS Windows it is $APPDATA\GRASS7\addons. The
directory is stored in GRASS_ADDON_BASE environmental variable.
The flag -s changes this install target directory to the GRASS GIS installation directory
(determined by GISBASE environmental variable, e.g. /usr/) rather than the default
GRASS_ADDON_BASE directory (see also documentation for variables). g.extension checks if
the user has permission to write to GISBASE or GRASS_ADDON_BASE.
The place where the extensions are installed can be customized by the option prefix.
Ensuring that these extensions will be accessible in GRASS GIS is then responsibility of
Compilation and installation
On MS Windows systems, where compilation tools not readily available, g.extension
downloads a compiled executable from the GRASS GIS project server. On all other operating
systems where it is not difficult to install compilation tools, g.extension downloads the
source code of the requested extension (addon) and compiles it locally. This applies for
both C and Python modules as well as any other extensions. The reason is that more things
such as manual page are compiled, not only the source code (which is really necessary to
compile just in case of C).
Download and install of an extension
Download and install r.stream.distance into current GRASS installation
This installs the extension from the official repository. For convenience, a shorter
syntax can be used:
Download and install of an extension when behind a proxy
Example for an open http proxy:
# syntax: http://proxyurl:proxyport
g.extension extension=r.stream.distance proxy="http://proxy.example.com:8080"
Example for a proxy with proxy authentication:
# syntax: http://username:password@proxyurl:proxyport
g.extension extension=r.stream.distance proxy="http://username:email@example.com:8080"
Managing the extensions
List all available extensions in the official GRASS GIS Addons repository:
List all locally installed extensions:
Removal of a locally installed extension:
g.extension extension=r.stream.distance operation=remove
Since extensions have to be compiled on Unix based systems (Linux, Mac OSX etc.) unless a
Python extension is installed, a full compiler environment must be present on the user’s
ERROR: Please install GRASS development package
While GRASS GIS is available on the user’s computer, the respective development package is
lacking. If GRASS was installed from a (Linux) repository, also the grass-dev* package
(commonly named "grass-dev" or "grass-devel", sometimes along with the version number)
must be installed.
Use g.extensiongrass online using onworks.net services