[GRASSLIST:1946] Re: Export Raster - followup

[Daniel Victoria]

Once again, thanks Glynn,

After reading the e-mail a couple of times I finaly
understood everything... Things are allways more
complicated then what they seam....

I'll see if later this week I'll make some changes on
the script. If not usable, it will at least be a cool
exercise

Thanks again for the eye opener

Daniel


--- Glynn Clements <glynn.clements at virgin.net> wrote:
> 
> Daniel Victoria wrote:
> 
> > Just to finish the topic.
> > 
> > I made 2 shell scripts, one that will tar/bzip2
> all
> > maps with a specific name to a tar.bz2 file and
> the
> > other that will unpack it. The unpacking is not
> > necessary since it can be done by simply using the
> > command
> > tar -jxPvf file_name
> > the P is to keep the original file path
> > 
> > Hope it can be usefull to anyone. Feel free to
> change
> > it as you see fit
> 
> > tar -jcPvf $outfile
> > $GISDBASE/$LOCATION_NAME/$MAPSET/*/$pattern
> 
> Presumably this was meant to be a single line, but
> was wrapped by your
> mail client?
> 
> A few points:
> 
> 1. You can't rely upon $GISDBASE, $LOCATION_NAME or
> $MAPSET being set;
> in 5.0.0 and later, these settings aren't stored in
> environment
> variables. The script would need to do:
> 
> 	eval `g.gisenv`
> 
> to set those variables.
> 
> 2. One potential problem with using absolute
> pathnames is that you
> might exceed the maximum length of a command line,
> particularly if
> $GISDBASE is long and a map has a large number of
> components. If you
> want complete pathnames in the tar file, a more
> reliable approach
> would be:
> 
> 	dir="$GISDBASE/$LOCATION_NAME/$MAPSET"
> 	cd "$dir"
> 	for file in */$pattern ; do
> 	    echo "$dir/$file"
> 	done | tar cjPvfT "$outfile" -
> 
> 3. Personally, I wouldn't use absolute paths, but
> would at least make
> them relative to $GISDBASE, so that they can still
> be extracted if
> $GISDBASE moves. E.g.
> 
> 	root="$GISDBASE"
> 	dir="$LOCATION_NAME/$MAPSET"
> 	( cd "$root/$dir"
> 	  for file in */$pattern ; do
> 	      echo "$dir/$file"
> 	  done ) | tar cjPvCfT "$root" "$outfile" -
> 
> A similar argument could be made about using paths
> which are relative
> to either the location or mapset directory. However,
> the arguments for
> including either the location or location+mapset
> directories are
> somewhat stronger than for the database directory
> (i.e. they form part
> of the database' structure).
> 
> Having said all that, the ultimate solution would be
> to use the code
> in src/general/manage (g.copy etc) to produce a
> utility which lists
> all of the files which actually comprise a map (via
> etc/element_list).
>  
> That would eliminate false positives, i.e. files
> with the same name as
> a map but which aren't actually part of that map.
> This is particularly
> relevant if you have raster/vector/sites maps with
> the same name.
> 
> -- 
> Glynn Clements <glynn.clements at virgin.net>
> 


__________________________________
Do you Yahoo!?
Free Pop-Up Blocker - Get it now
http://companion.yahoo.com/