[GRASS5] raster file history question

[Eric G. Miller]

On Thu, Apr 04, 2002 at 02:10:48PM +0200, Markus Neteler wrote:
> On Thu, Apr 04, 2002 at 12:32:19PM +0200, Bernhard Reiter wrote:
> > On Wed, Apr 03, 2002 at 06:29:37PM +0200, Markus Neteler wrote:
> > > for a few modules I would like to add the feature that
> > > the invoking command lines is stored into the raster file history.
> > > 
> > > It will be trivial, but I don't get the command line into
> > > a string.
> > 
> > Maybe it is just me, but I don't understand the question.
> 
> Ok, sorry for boing unclear. A new try:
> 
> I want to store the command line, which was used to start a
> module, into the history section of data.
> 
> Example: I run
> 
> r.proj dgm1km loc=europa map=europa
> When I now run
> 
>  r.info dgm1km
> 
> the string "r.proj dgm1km loc=europa map=europa" should appear in
> the history. This is implemented in r.slope.aspect and s.surf.rst,
> but more complicated there. For my module (not r.proj) the command line
> string is sufficient to later remember the parameters which I used to
> generate that particular map.
> 
> It must be something with argv[] or so.

The developer's guide says programs need not be concerned about the
history file.  Also, says the history mechanism is in need of an
overhaul.  On quick inspection of the struct, all I can say is there'd
be no easy way to just append a line to an existing history.  You'd
have to go through each line looking for an opening.  Also, it's
possible a command would be longer than RECORD_LEN, so would need to
be split across lines.

-- 
Eric G. Miller <egm2 at jps.net>