Message-ID: <alpine.LFD.2.20.1604152046460.24113@reclus.nhh.no>
Date: 2016-04-15T18:58:15Z
From: Roger Bivand
Subject: GISRC environment variable using initGRASS
In-Reply-To: <DUB129-W573D763DAB1ABA9C09EF8BA5680@phx.gbl>
On Fri, 15 Apr 2016, Roger B?r wrote:
> I am currently using the R package "rgrass7" (Version: 0.1-6) in order
> to command GRASS GIS (Windows7, OSGEO4W installation).
>
> I use R in order to start a GRASS environment and to script my
> geoprocessing. Both is working fine. However, I have problems with
> storing and calling the GRASS gisenv variables. Every time when I call
> "initGRASS" a file called "junk" is created containing GRASS gisenv
> variables.
>
What the file is called is probably immaterial.
>
> Looking at the source of the initGRASS function the section below
> puzzeled me somehow:
>
> ?59 ? Sys.setenv(GISRC = paste(Sys.getenv("HOME"), "\\.grassrc7",?
> ?60 ? ? sep = ""))
This is setting GISRC to a value
> ?61 ? if (file.exists(Sys.getenv("GISRC")) && !override)?
> ?62 ? ? stop("A GISRC file already exists; to override, set override=TRUE")
> ?63 ?Sys.setenv(GISRC = "junk")
This is setting it again in the working directory - I don't recall why -
probably frustration years ago with Windows.
> ?64 ?cat("GISDBASE:", getwd(), "\n", file = Sys.getenv("GISRC"))
> ?65 ?cat("LOCATION_NAME: <UNKNOWN>", "\n", file = Sys.getenv("GISRC"),?
> ?66 ? ? append = TRUE)
> ?67 ?cat("MAPSET: <UNKNOWN>", "\n", file = Sys.getenv("GISRC"),?
> ?68 ? ? append = TRUE)
> ?69 ?gisrc <- ifelse(use_g.dirseps.exe, system(paste("g.dirseps.exe -g",?
> ?70 ? ? shQuote(Sys.getenv("GISRC"))), intern = TRUE), Sys.getenv("GISRC"))
> ?71 ? assign("addEXE", .addexe(), envir = .GRASS_CACHE)
> ? 72 ?Sys.setenv(GISRC = gisrc)
>
And this sets it again. It is set, otherwise GRASS wouldn't work;
programmatically you'd have to use Sys.getenv("GISRC") to get the value.
Please provide a use case where this matters, and consider moving this
thread to the statsgrass list.
Hope this helps (doesn't clarify, but that's legacy Windows),
Roger
> First, why is initGRASS using ".grassrc7" for storing the GISRC file??
> InitGRASS is looking for the GISRC file under ".grassrc7" (line 59). However, in the?package documentation [1], the GISRC file is called ".gisrc". Moreover, the?GRASS documentation?says that the GISRC file is stored under "/.grass7/rc"
>
> Second, what is the purpose of assigning "junk" to the GISRC environment variable??
> GISRC is set to "junk" (line 63) and then the GISRC value ("junk") is assigned again back to system variable GISRC. Unless I misinterpreded the code, it does not make much sense to me. Shouldn't the enviroment varibales not be written (line 64 - 68) to ".grassrc7" rather than to "junk"?
>
>
>
> I would appreciate any support or hints!
>
> Regards,
> Roger
>
> [1] http://https//cran.r-project.org/web/packages/rgrass7/rgrass7.pdf
> [2]?http://grass.osgeo.org/grass70/manuals/variables.html
>
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>
--
Roger Bivand
Department of Economics, Norwegian School of Economics,
Helleveien 30, N-5045 Bergen, Norway.
voice: +47 55 95 93 55; fax +47 55 95 91 00
e-mail: Roger.Bivand at nhh.no
http://orcid.org/0000-0003-2392-6140
https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
http://depsy.org/person/434412