Re: [RFC] usage of environment variable from the command line

[Daniel Jacobowitz <drow at false dot org>]

On Sat, Sep 22, 2007 at 09:16:38AM +0200, Eli Zaretskii wrote:
> > Before we go ahead with this can anyone think of a better one that
> > won't conflict with source language expressions?
> 
> How about env("FOO") ?  Or maybe $env("FOO"), to avoid a possibility
> that the debuggee has a real function by the name of `env'?

I like $env("FOO") or $ENV("FOO").

> > Another problem is escaping.  Right now, you're supposed to be able to
> > give either quoted strings or raw text to most commands (it
> > varies, I posted a summary a while back).  Front ends won't know how
> > to escape the string if you have e.g. %% in your $PWD or want to
> > print a string containing %%.
> 
> The above suggestion solves this problem as well, I think.

Mostly yes.  The context where environment variables would be most
useful is in places we don't take expressions, like after the
"file" command; we've been changing those to take quoted strings
to handle spaces and backslashes safely, so we could allow
backslash to escape dollar sign too.

Do we want environment variable support only for things that take text
(pathnames, filenames, string values), or do we also want it in C
expression contexts?  If only the former, maybe $ENV(HOME) without
the inner quotes; quotes are already special.

-- 
Daniel Jacobowitz
CodeSourcery