Re: find (and friends) bug?

[Tom Lord]

       From: fabrice bauzac <address@hidden>

       POSIX awk regex syntax
       POSIX egrep regex syntax
       extended POSIX syntax

       As you can see, there are many syntaxes for regular expressions.

Aren't all three of those the same (Posix ERE)?  Or are awk and egrep
cases where its "ERE with a slight variation"?  If the latter, can you 
site ANSI/IEEE 1003.2 paragraphs?

      GNU awk regex syntax
      [GNU] egrep regex syntax

And aren't those two ERE with upward compatible extensions?  I would
agree that the extensions should be enabled only by an explicit
option, but it is probably too late now to do that without breaking
lots of people's scripts.

        common POSIX syntax
        basic POSIX syntax

What is "common POSIX syntax"?  So far as I know, Posix precisely
defines BRE and ERE, and some minor exceptions to those syntaxes for
particular commands.

In other words, as far as Posix and the tools you mention are
concerned, there are essentially four syntaxes, not seven:

        Posix BRE               Posix BRE with GNU extensions
        Posix ERE               Posix ERE with GNU extensions

There's a separate issue -- that GNU regex doesn't accurately
implement Posix [BE]RE -- but that's another thing that can't
_obviously_ be fixed without breaking lots of people's scripts.
Maybe it can; maybe it can't.

-t