Re: [PATCH 1/3] Properly expand @configure_input@ in config.status.

[Paolo Bonzini]

Paul Eggert wrote:
> Paolo Bonzini <address@hidden> writes:
>
> > Yes, it is undefined
>
> I don't see why 's&foo&\&&' is undefined.  The POSIX standard says:
>
>    Any character other than backslash or <newline> can be used instead
>    of a slash to delimit the BRE and the replacement. Within the BRE
>    and the replacement, the BRE delimiter itself can be used as a
>    literal character if it is preceded by a backslash.
>
> Therefore, preceding & by a backslash makes it a "literal character",
> i.e., a character that is not special.  Where's the ambiguity?

I'm interested in how other seds behave for say

s{a\{1,2\}{b{

since the current way GNU sed works for the RHS depends on a change in 
the interpretation of the RHS.

Paolo