Subj : Re: Using javascript as an interactive command language
To   : Robert Mecklenburg <mecklen@realmsys.com>
From : Brendan Eich <brendan@meer.net>
Date : Tue Mar 30 2004 08:26 pm

Robert Mecklenburg wrote:
> I'm implementing an interactive (but scriptable) command language. 
> Expressions in this language look like:
> 
> list all users
> pushd key
> set debug on
> 
> I would like to use javascript as the basic interpreter for this
> language, but I'm having trouble knitting my syntax together with js
> syntax.
> 
> I can imagine a bash-like behavior where things that don't immediately
> look like javascript are handled by my own parser, while the rest is
> handled by js.  Of course, I'd like to be able to use variables from
> js in my own commands.  Like:
> 
> list -l $users
> 
> where $users is the contents of a js variable.
> 
> Any suggestions on how to do this?

Ancient progenitor versions of the js shell 
(http://lxr.mozilla.org/mozilla/source/js/src/js.c) used to preprocess 
the command line to turn list -l $users into list("-l", $users) or 
something like that.  I wrote the hack, but I actually forget the 
details, and the code was removed long before mozilla.org released 
js/src into the open.

Is it important to preprocess into JS?  You'll find endless tension 
between the pre- and post-processed languages.  Better to use pure JS, 
or something like pure bash.  Mixing leaves you in a muddle, too often.

/be

.