[Gretl-devel] dotdir

[Allin Cottrell]

On Thu, 3 May 2007, Sven Schreiber wrote:

> Allin Cottrell schrieb:
> 
> > 1. When gretl starts, we record the initial CWD and set shelldir 
> > to this value.
> 
> I actually thought this was already the case, so I'm all for it.

Yes, it makes a lot of sense and I should have thought of it
before.

> > 2. When we come across a filename in a store or outfile (or 
> > similar gretl) command we do the following:
> > 
> > (a) If it's an absolute path, respect it (of course).
> 
> Yes.
> 
> > (b) If it's a plain filename with no explicit path element,
> >     we take it that @userdir is implied.
> 
> No I think gretl should rather respect the user preference setting
> (userdir or CWD) in this case. (Or else get rid of this preference
> option in gretl and leave that stuff to the desktop environment.)

OK, I can go with that.

> > (c) If it's a "./" filename we use shelldir.
> > (d) Shelldir can be changed by the user via the set command, 
> >     and this will be respected in context (c).
> 
> For (c) I repeat that I would prefer to leave "./" untouched 
> after startup. What's the advantage for a user of being able to 
> change ./? 

Well, basically the same as being able to do "cd" in the shell 
itself.  You can then do things without having to type (possibly 
long and possibly "have-to-be-wrapped-in-quotes" filenames).

> Now ad (d): I like the idea very much that the context directory 
> for "!" can be set by a script. (I hope that's what it means.)

Yes, that's the primary intent behind "set shelldir".  

> > In the context of actual "!" shell calls, you can of course do as 
> > you like, giving absolute paths, using the @userdir variable, 
> > setting shelldir, using "cd", or whatever.  I don't propose trying 
> > to push output into @userdir in that context.
> 
> Now I don't quite understand this;  I thought everything in a "!" line
> after the ! would be just passed literally to the OS's shell. That means
> I can type in absolute paths, or previously doing a "set shelldir" etc.,
> but how can I use variables? 

> For example, this does not work (I never thought it would):
> 
> ? ! python -c "f=open('@userdir\test.txt', 'w'); f.close()"

This must be one of those wretched backslash things; it works fine 
on Linux

? ! touch @userdir/test.file
? ! touch '@userdir/test.file'

Both are OK.  I'll try some testing on Windows. 

> So altogether my suggestions would imply:
> 
> 1) If a script author wants to use the gretl user directory or some
> relative path based on that (ignoring the user's preferences), she must
> use the @userdir variable for store/outfile and shelldir.

Yes, fine.

> 2) If a script author wants to honor the user's preferences, she must
> simply use a relative path to end up either in the gretl user dir or in
> the CWD.

Ditto.

> 3) If a script author wants to enforce the CWD, use "./"

Again, OK.

> What's not possible by gretl's design is to use $HOME (or 
> whatever it's called), or did you already implement Jack's 
> getenv suggestion?

Not yet; maybe later today.

I think the only point on which we're not quite agreed is whether 
it makes sense to have "set shelldir" work as a sort of "cd" which 
affects the default path for outfile and so on.  But I don't have 
very strong feelings about that, and I can see that it might be 
cleaner to let shelldir affect only shell commands.

Allin.