Path: csiph.com!news.mixmin.net!aioe.org!.POSTED!not-for-mail
From: "Helmut Karlowski" <helmut.karlowski@ish.de>
Newsgroups: gnu.bash.bug
Subject: Re: \c-handling in $'-strings
Date: Wed, 02 Sep 2015 22:10:45 +0100
Organization: Aioe.org NNTP Server
Lines: 41
Message-ID: <op.x4cs37v5ofd6j1@nebbiolo.upc.de>
References: <op.x33p5xjhofd6j1@nebbiolo.upc.de> <mailman.248.1441030661.19560.bug-bash@gnu.org> <op.x4a2vqn6ofd6j1@nebbiolo.upc.de> <mailman.388.1441199993.19560.bug-bash@gnu.org>
NNTP-Posting-Host: KI55aZ7LNnCoM32DfYXE9Q.user.speranza.aioe.org
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit
X-Complaints-To: abuse@aioe.org
User-Agent: Opera Mail/12.16 (Win32)
X-Antivirus-Status: Clean
X-Notice: Filtered by postfilter v. 0.8.2
X-Antivirus: avast! (VPS 150902-1, 02.09.2015), Outbound message
Xref: csiph.com gnu.bash.bug:11472

Am 02.09.2015, 14:19 Uhr,SCHRIEB Chet Ramey <chet.ramey@case.edu>:

>> echo $'\c?' |od -a
>> echo $'\c[\c\\c]\c^\c_\c?' |od -a
>>
>> bash prints:
>>
>> 0000000  us  nl
>> 0000002
>> 0000000 esc  fs   c   ]  rs  us  us  nl
>>
>> I'd expect:
>>
>> 0000000 del  nl
>> 0000002
>> 0000000 esc  fs  gs  rs  us del  nl
>>
>> Also the ] in the output seems wrong, looks it gets the \\ wrong, though
>> ksh93 does this also.
>
> The Posix standardization of $'...' requires that the character after the

Where is that described? I could not find anything about $'...' in the  
posix-docs.

> `\c' honor backslash escaping.  Since the character becomes \c\\, the
> subsequent `c' and `]' are literals.

I assume this is only true for "to-be-escaped" characters, that is

$   `   "   \   <newline>

like for ".."-strings? Of course only \ is of interest here.

If that is true then the output of ksh93 for

echo $'\c\d' |od -a -> 0000000 eot  nl

is wrong? It removes the \ every time.

-Helmut