From: Jakub Narebski <jnareb@gmail.com>
Date: Sun, 31 Aug 2008 20:55:15 GMT
Subject: Re: [PATCH] change Perl syntax to support Perl 5.6
Message-ID: <200808312255.16943.jnareb@gmail.com>
In-Reply-To: <200808312223.38222.jnareb@gmail.com>

Jakub Narebski wrote:

> We have to go to quote.c to get to know why "!" is a special case too,
> in addition to "'".  The commit message for 77d604c3 (by H. Peter Anvin,
> which is CC-ed) states:
> 
>     Create function to sq_quote into a buffer
>     Handle !'s for csh-based shells

Although according to POSIX 

  Enclosing characters in single-quotes ( '' ) shall preserve the literal
  value of each character within the single-quotes. A single-quote cannot
  occur within single-quotes.

so "!" should be not treated as special character in POSIX shell,
csh unfortunately does not follow this.  Try

  $ echo '!!'

in csh, tcsh (now that's funny) and bash (or dash).

-- 
Jakub Narebski
Poland