Re: Ada.Command_Line and wildcards

[Jacob Sparre Andersen <sparre@nbi.dk>]

Markus E Leypold wrote:

> I admit that, but I find your use of "Unix" still problematic
> here. First, the kernel itself doesn't know ynthiong about text
> substitution. Second, text substitution is something implemented in
> a lot of Unix tools (cpp, m4, sed, awk) and it is often exactly what
> one needs to process text.

But C, the system call interface and sh(1) are all a part of the Unix
design and system. - Even if a part of the design is that some parts
of it can be changed.

We shouldn't ignore this.  And in a historical context, this design is
probably rather good.  We should rather look at how we can use our
experience with the system (and what we've built on top of it) to
create an even better one.

> I wouldn't want to use Ada as an interactive command language. There
> are, I think, ways to get (1) type safety, (2) proper quoting
> without too much overhead. I, personally, would built a new
> generation shell system on, ahem, OCaml, because of the type
> interference and because functional composition might take the part
> pipes have played in the past.

I'm not sure I would use OCaml as the basis.  To me it seems too big
and complicated for the purpose.  But the shell (interactive command
language) should support all the different kinds of interprocess
communication that the underlying kernel supports.  That doesn't quite
seem to be the case with sh(1).

>> Suggesting replacement parts for pieces of Unix really means
>> suggesting to change its design.
>
> No. I do think you use the word design in rather too broad a
> sense. Else we could never change ynthing without "changing the
> design".
>
> One must perhaps live with the notion that no OS is just amonolithic
> complex of design choices. It is not simply a "design change" if I
> (user) change to another shell (that is designed to be user
> replacable, BTW).

Since sh(1) is a requirement in the POSIX standard, it is a change in
the design to substitute sh(1) with something else (although it is a
change the remaining system is designed to allow).  Adding yet another
user selectable shell to the system is on the other hand not something
I consider a change in the design.

Greetings,

Jacob
-- 
"The universe isn't for the likes of me to understand. I only work here."