From: Peter Stephenson <p.stephenson@samsung.com>
To: Martijn Dekker <martijn@inlv.org>, zsh-workers@zsh.org
Subject: Re: 'case' pattern matching bug with bracket expressions
Date: Thu, 14 May 2015 18:43:32 +0100 [thread overview]
Message-ID: <20150514184332.3803584d@pwslap01u.europe.root.pri> (raw)
In-Reply-To: <5554D65B.8070500@inlv.org>
On Thu, 14 May 2015 18:07:39 +0100
Martijn Dekker <martijn@inlv.org> wrote:
> However, the more insidious case that bit me:
>
> case abc in ( [] | [!a-z]* ) echo yes ;; ( * ) echo no ;; esac
> empty=''
> case abc in ( ["$empty"] | [!a-z]* ) echo yes ;; ( * ) echo no ;; esac
>
> still produces a false positive even with the patch.
This is hairy because you're relying on whitespace performing word
splitting in a case where you don't need whitespace according to the
grammar anyway, i.e. if you have the valid expression
case abc in (["$empty"]|[!a-z]*) echo yes ;; (*) echo no ;; esac
it can only be parsed the way zsh parses it --- you'll find bash does
the same.
I'll have a look at changing the way we handle whitespace in
bracketed expressions in POSIX mode (POSIX_STRINGS option? That's
about the closest I can see and underworked at the moment).
The above still needs some work, though, since we don't currently word
split case statements. I think that probably is required by the
standard since it specifies word (though not word list) handling,
i.e. implying the same as command line words but with an additional "|"
token between words. That's probably going to have to wait till after
5.0.8.
pws
next prev parent reply other threads:[~2015-05-14 17:43 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-14 13:14 Martijn Dekker
2015-05-14 13:50 ` [BUG] " Martijn Dekker
2015-05-14 14:42 ` Peter Stephenson
2015-05-14 15:47 ` Martijn Dekker
2015-05-14 15:55 ` Peter Stephenson
2015-05-14 17:30 ` Bart Schaefer
2015-05-15 0:05 ` Chet Ramey
2015-05-14 23:51 ` Chet Ramey
2015-05-15 8:38 ` Peter Stephenson
2015-05-15 20:48 ` Peter Stephenson
2015-05-15 21:48 ` Bart Schaefer
2015-05-14 16:17 ` Peter Stephenson
2015-05-14 17:07 ` Martijn Dekker
2015-05-14 17:43 ` Peter Stephenson [this message]
2015-05-15 0:09 ` Chet Ramey
2015-05-14 23:59 ` Chet Ramey
2015-05-14 21:23 ` Chet Ramey
2015-05-14 23:45 ` Chet Ramey
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