[GRASS-dev] r.mapcalc changed to use G_parser()

[Jachym Cepicky]

wow!

j

2008/8/6 Glynn Clements <glynn at gclements.plus.com>:
>
> I have changed r.mapcalc in 7.x to use G_parser():
>
>        $ r.mapcalc --help
>
>        Description:
>         Raster map calculator.
>
>        Keywords:
>         raster
>
>        Usage:
>         r.mapcalc [expression=string] [input=name] [--overwrite] [--verbose]
>           [--quiet]
>
>        Flags:
>         --o   Allow output files to overwrite existing files
>         --v   Verbose module output
>         --q   Quiet module output
>
>        Parameters:
>          expression   Expression to evaluate
>               input   File containing expression to evaluate
>
> Note that, as expression= is the first option, it is the default. This
> means that passing an expression on the command line is compatible
> with both the old and new interfaces, so long as you:
>
> a) quote the expression, and
> b) include a space before the first = sign.
>
> E.g.:
>        r.mapcalc "foo = 1"
> or:
>        r.mapcalc 'foo = 1'
>
> An unquoted expression (i.e. split over multiple arguments) won't
> work, nor will omitting the space before the = sign:
>
>        $ r.mapcalc 'foo=1'
>        Sorry, <foo> is not a valid parameter
>
> If no options are given, it manufactures "input=-" (which reads from
> stdin), so you can continue to use e.g.:
>
>        r.mapcalc < file
> or:
>        r.mapcalc <<EOF
>        foo = 1
>        EOF
>
> But unless you need compatibility with previous versions, use input=
> explicitly, e.g.:
>
>        r.mapcalc input=file
> or:
>        r.mapcalc input=- <<EOF
>        foo = 1
>        EOF
>
> Also, it now recognises --o[verwrite] and $GRASS_OVERWRITE, so you
> will get an error if you try to overwrite an existing map without one
> of those.
>
> Note that older versions don't understand --o, so if you want to write
> a shell script which is compatible with both versions, and which will
> overwrite existing maps, use e.g.:
>
>        GRASS_OVERWRITE=1 r.mapcalc 'foo = 1'
>
> Python scripts only need to work with 7.x, so you can just use --o (or
> overwrite=True with grass.run_command etc).
>
> --
> Glynn Clements <glynn at gclements.plus.com>
> _______________________________________________
> grass-dev mailing list
> grass-dev at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/grass-dev
>



-- 
Jachym Cepicky
e-mail: jachym.cepicky gmail com
URL: http://les-ejk.cz
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