Re: tilde featuritis alert

[Decklin Foster <fosterd@hartwick.edu>]

Gert-Jan Vons writes:

> Something like "if (~ a b || ~ c d)" becomes quite messy when you
> only have 'switch'.

Ah, true.

> I doubt you will see tilde expansion in rc anytime soon, since it
> doesn't go with the philosophy behind the shell (just look at the
> debates over 'echo' being built-in or not).

Yeah, i read up on the archives and I see what you mean; I don't agree
with the idea that tilde expansion makes rc more bloated or somehow
doesn't 'belong' in a shell (computers are supposed to work for us,
not the other way around, no?) I was just hoping that perhaps someone
else who was bothered by this had already done the work of writing a
patch.

> I've been thinking and discussing a bit with other rc/vrl users
> about adding ~ expansion to the vrl command-line editor, but it
> ain't that simple since there's no easy way to know whether the user
> wants the ~ to be the ~ operator or not.

I bet i can get readline to do this before passing the command to rc,
now that I think of this. After all, it *does* come from the people
who brought you (ick) Emacs. ;-)

> Something that I still haven't gotten used to even after 5-6 years
> of using rc is the need to quote command arguments if there's an
> equal sign like in "dd 'if=infile' 'of=outfile'".

It seems to me that a simple rule would suffice here. An '=' in the
first word of a command is interpreted as a metacharacter. An '=' in
the rest of it is not. Oh, but there is the issue of 'foo = bar' (I
find myself trying to do that frequently in sh now.) OK, an unquoted
'=' is a metacharacter iff (it's part of the first word || it's the
first character in the second word). That should continue to allow
'foo =bar' as well.

Does lex/yacc let us do this? I'm not much of an expert there.

-- 
Decklin
Written with Debian GNU/Linux - http://www.debian.org/