[GRASS-user] result from g.copy when layer exists

Rainer M Krug Rainer at krugs.de
Wed Jul 17 23:39:37 PDT 2013

Glynn Clements <glynn at gclements.plus.com> writes:

> Rainer M Krug wrote:
>> I am a bit irritated,  ut maybe I don't dee the reasoning behind this:'
>> ,----
>> | RASS 7.0.svn (grass):~ > g.copy rast=MASK,tmp
>> | WARNING: <tmp> already exists
>> | [Raster MASK present]
>> | GRASS 7.0.svn (grass):~ > 
>> `----
>> If the layer already exists, shouldn't the command give actually an
>> error and not only a warning?
>> A warning implies for me that the command worked, but maybe something
>> unexpected could have happened (or happened) - but this one clearly did
>> not work, as the layer has not been copied?
> In GRASS, errors are fatal; the program will be terminated as soon as
> the error message has been printed.

Exactly - if e.g. in r.mapcalc an invalid expression is entered,
r.mapcalc issues the error message and quits.

> Each of g.copy's options accept an arbitray number of
> source+destination pairs, and the various options aren't mutually
> exclusive (e.g. a single invocation can copy both raster and vector
> maps).


> If it can't perform a particular copy for any reason, it generates a
> warning then moves on to the next item.

True - but this does not answer my question. But I looked at cp in bash,
and it behaves in the same way.
So I think I have to live with this.



Rainer M. Krug

email: RMKrug<at>gmail<dot>com

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