are there any patches which add ~ expansion to rc

are there any patches which add ~ expansion to rc

[Joseph Skinner]

Hi

the title just about says it all.

This is one of the few things that I miss from bash and have noted that
this has been added to es.

What is the general view of this being part of rc.

Also where can I get the latest version of rc and it still being 
actively developed.

Joe.

-- 
=======================================================================
in real life: Joseph Skinner         |There's no such thing as a wizard
email: joe@earthlight.co.nz          |who minds his own business
       jskinner@es.co.nz             | - Berengis the Black
http:  www.earthlight.co.nz/users/joe|   Court Mage to the Earls Caeline
========================================================================

Re: are there any patches which add ~ expansion to rc

[Scott Schwartz]

Joseph Skinner <joe@earthlight.co.nz> writes:
| What is the general view of this being part of rc.

Wrong level of abstraction.  Your os should provide a (virtual)
filesystem mounted on "/u" so you can say /u/username in every
context.  Sun's automounter can almost do this right; amd can
probably do better.

Re: are there any patches which add ~ expansion to rc

[Mark K. Gardner]

Joe,

A while ago I hacked rc to add ~ expansion. (It was a real kludge.)
However, after thinking about it more I decided that expansion really
belongs in readline/editline. So I modified readline v2.1 to support
it. I then had to make a relatively minor change to rc to initialize
readline properly and to perform expansion.

[Caveat: I decided not to use ~ because of its obvious conflict with
pattern matching in rc. Instead I used % which seems to be free. It
would have been better if the final expansion was done in readline,
but it appeared that readline would be too easy to break.]

The modification works fine. I have to remember to use ~ instead of %
in emacs though! The patch is too long to post and is of (perhaps)
limited interest so I will email it to you directly.

Mark

-- 
Mark K. Gardner (mkgardne@cs.uiuc.edu)
University of Illinois at Urbana-Champaign
Real-Time Systems Laboratory
-- 

Re: are there any patches which add ~ expansion to rc

[Tim Goodwin]

> What is the general view of this being part of rc.

I agree with Scott that this should be in the filesystem.  If not, you
have to add it to every last application that uses filenames.  (Here,
`/home/foo' works everywhere for all foo, although I'm not entirely
happy about the symlink farm that makes it happen...)

> Also where can I get the latest version of rc and it still being 
> actively developed.

The latest full release is still 1.4, but you might like to try the
latest beta release 1.5b2.  You can get it from these places.

    ftp://ftp.sys.utoronto.ca/pub/rc/rc-1.5b2.tar.gz
    ftp://ftp.pipex.net/people/tim/rc-1.5b2.tar.gz

Let me know if you don't have the one-line patch I posted to the list
the other day.

Tim.

Re: are there any patches which add ~ expansion to rc

[Chris Siebenmann]

 Our local solution is a /u directory (automatically) populated with
symlinks that point to the appropriate places. We've been running it
for years without problems; I can mail people copies of either a sh
or a perl version[*] of the script that maintains /u if desired.

 I've repeatedly found it very handy to have a short name for home
directories that works in every program and situation. And better
yet there's no need to clog up umpteen programs with code to do ~
expansion.

	- cks
[*: yes, I know I was giving in to the evil empire, but I decided I
    needed a decently fast program for the system with circa 10,000
    passwd entries.]

Re: are there any patches which add ~ expansion to rc

[Jeremy Fitzhardinge]

On Sep 18,  7:26pm, Chris Siebenmann wrote:
>  Our local solution is a /u directory (automatically) populated with
> symlinks that point to the appropriate places. We've been running it
> for years without problems; I can mail people copies of either a sh
> or a perl version[*] of the script that maintains /u if desired.

While I agree that /u is an elegant approach to dealing with the ~user
problem, the most common use of ~ is when referring to one's own
home directory, which /u doesn't help with.  I once implemented /u
as a user-space filesystem under Linux which generated its contents
on demand from /etc/passwd. It also had a /u/me which always referred
to the caller's home direcory, which is hard to do with a conventional
symlink /u.

The $H solution is OK for rc, but it has the same problems as ~, in that
not everything will understand it.

	J

Re: are there any patches which add ~ expansion to rc

[Steve_Kilbane]

> While I agree that /u is an elegant approach to dealing with the ~user
> problem, the most common use of ~ is when referring to one's own
> home directory, which /u doesn't help with.

True, but then, the problem lies in the ~ semantics, which aren't
great. Just as /u/foo can point to user foo's directory, /me (or /m)
can point to the current user's. Naturally, this needs special
handling in UNIX (as in /proc, /fd), and can be put in $home/lib/profile
in Plan 9.

What's really annoying is that this is one of the few things that
DOS can handle, and plain ol' UNIX can't.

Re: are there any patches which add ~ expansion to rc

[arnold]

> the title just about says it all.

I think I did it years ago, it's pretty easy.

If you use GNU readline with rc, I (long ago) added ESC-& (I think)
to do ~ expansion (in vi mode). Try that and see if it still works.
(I use 9term and es).
---
Arnold Robbins		Internet: arnold@gnu.ai.mit.edu