From: H. Peter Anvin <hpa@zytor.com>
Date: Thu, 15 Sep 2005 20:18:13 GMT
Subject: Re: Shell quoting
Message-ID: <4329D705.8050101@zytor.com>
In-Reply-To: <7vll1yyusn.fsf@assigned-by-dhcp.cox.net>

Junio C Hamano wrote:
> "H. Peter Anvin" <hpa@zytor.com> writes:
> 
> 
>>Linus Torvalds wrote:
>>
>>>Does anybody really still use tcsh? It's a broken mess.
>>>
>>
>>Yes.
> 
> Yes to "still use", or yes to "broken mess" ;-)?
> 

Both :)

>>>Junio's "sq_quote()" works wonderfully on any valid shells. The fact
>>>that tcsh expands ! even inside single quotes is just pure
>>>braindamage.
>>
>>>You could expand "sq_quote" to handle '!' and '\' characters the exact
>>>same way it handles the single tick (end single-tick quoting, do \! or \\
>>>and start single-tick quoting again) and that might be good enough for
>>>tcsh.
>>
>>It seems easier to just \-escape any special characters.
> 
> I am sympathetic.  The beauty of sq_quote() comes directly from
> the behaviour of single quoting rules of "any valid shells" --
> there is no need to maintain a list of special characters.  Just
> single quote itself is special and nothing else.

Well, in the patch I just posted I simply \-escape a blacklist of 
characters.  It should be quite safe, since the blacklist consists of 
all ASCII characters that aren't known to be regularly used on the 
command line.

	-hpa