Re: sed POSIX compatibility regarding '|' in regular expressions

[Paolo Bonzini]

Bruno Haible wrote:
> Hi,
>
> POSIX states in [1], section "Regular Expressions in sed", that sed uses
> basic regular expressions, with three minor modifications. The syntax
> of basic regular expressions is defined in [2]. According to the text
> and to the "RE and Bracket Expression Grammar" section at the end of this
> page, POSIX BREs don't support alternation. "The interpretation of an ordinary
> character preceded by a backslash ( '\' ) is undefined" - so this means
> that the use of '\|' in BREs is a GNU extension.
>
> Bug #1: The --posix option fails to turn off this GNU extension.

This is not a bug, as Eric already explained.

As for the build failures, I think that the complete switch to gnulib 
has fixed them (from last September, see CVS sed).  Actually, at the 
time 4.1.5 was released regex was taken from GNU libc, and you know how 
careful Uli is about portability for code in the glibc repository. :-) 
I will find time to prepare a new release soon.

Paolo