From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <zsh-workers-return-7382-mason-zsh=primenet.com.au@sunsite.auc.dk>
Received: (qmail 28632 invoked from network); 5 Aug 1999 14:41:38 -0000
Received: from sunsite.auc.dk (130.225.51.30)
  by ns1.primenet.com.au with SMTP; 5 Aug 1999 14:41:38 -0000
Received: (qmail 23727 invoked by alias); 5 Aug 1999 14:41:26 -0000
Mailing-List: contact zsh-workers-help@sunsite.auc.dk; run by ezmlm
Precedence: bulk
X-No-Archive: yes
X-Seq: 7382
Received: (qmail 23720 invoked from network); 5 Aug 1999 14:41:25 -0000
X-Envelope-Sender-Is: Andrej.Borsenkow@mow.siemens.ru (at relayer thoth.mch.sni.de)
From: "Andrej Borsenkow" <Andrej.Borsenkow@mow.siemens.ru>
To: "Sven Wischnowsky" <wischnow@informatik.hu-berlin.de>,
        <zsh-workers@sunsite.auc.dk>
Subject: RE: PATCH: parameter and quoting (was: Re: Completion problems.)
Date: Thu, 5 Aug 1999 18:41:23 +0400
Message-ID: <002d01bedf50$96ba92e0$21c9ca95@mow.siemens.ru>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="koi8-r"
Content-Transfer-Encoding: 7bit
X-Priority: 3 (Normal)
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)
In-Reply-To: <199908051426.QAA17397@beta.informatik.hu-berlin.de>
Importance: Normal
X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300

> Then Andrej Borsenkow wrote:
>
> > Unfortunately, Single UNIX requires, that quotes be matched. This
> is from the
> > description of double-quotes:
> >
> > ==
> > Within the string of characters from an enclosed ${ to the matching
> "}", an even
> > number of unescaped double-quotes or single-quotes, if any, must occur.
> > ==
> >
> > It means, that preceding example MUST be
> >
> > echo "${a%\'}"
>
> Damn, I just had the patch... but even if we decide to follow the
> standard and not ksh here, it will be easier with this patch.
>

Ehem ... reading it a bit more closely, it is still ambiguous. Single UNIX
explicitly diallows "${foo%'}" - but it does not tell us, how to actually escape
single quote in this case. Another line in the same paragraph says:

==
The backslash retains its special meaning as an escape character (see Escape
Character (Backslash) ) only when followed by one of the characters:
$   `   "   \   <newline>
==

OTOH it contains valid example:

unset bar
foo="${bar-\}}"

This implies, that in "${...}" backslash quotes } and (probably) ' ... horrors.

Anybody has better description?

/andrej