2012/4/8 ольга крыжановская <[email protected]>

> Clark, David, so \ has no special meaning to escape special characters
> like ], [, :, etc with in [] or is this undefined in the POSIX
> standard?
>

I've never read the POSIX standard about RE so I'm not sure if it's
required by POSIX. But based on my experience special chars need not be
escaped within [].

>
> Olga
>
> 2012/3/12 Clark J. Wang <[email protected]>:
> > 2012/3/10 Guido Berhoerster <[email protected]>
> >>
> >> * ольга крыжановская <[email protected]> [2012-03-09 20:19]:
> >> > Clark, can you point me to the section of the standard which defines
> >> > that ] must be the first characters in []? It feels not common sense,
> >> > unsymmetrical and sounds like a nightmare for parsers. I believed that
> >> > every character with a special meaning for extended regex must be
> >> > escaped in cases where the user wants the character literally. Does
> >> > the standard really define an exception here?
> >>
> >>
> >> >From the XBD Issue 7 IEEE Std 1003.1-2008, 9.3.5 RE Bracket Expression
> >> (online at
> >>
> http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03_05
> ):
> >>
> >>    1. ... The right-bracket ( ']' ) shall lose its special meaning and
> >>    represent itself in a bracket expression if it occurs first in the
> list
> >>    (after an initial circumflex ( '^' ), if any). Otherwise, it shall
> >>    terminate the bracket expression, unless it appears in a collating
> >> symbol
> >>    (such as "[.].]" ) or is the ending right-bracket for a collating
> >> symbol,
> >>    equivalence class, or character class.
> >
> >
> > On my Debian 6 system it's also mentioned in misc man pages like grep(1)
> and
> > regex(7).
> >>
> >>
> >> --
> >> Guido Berhoerster
> >> _______________________________________________
> >> ast-users mailing list
> >> [email protected]
> >> https://mailman.research.att.com/mailman/listinfo/ast-users
> >
> >
>
>
>
> --
>       ,   _                                    _   ,
>      { \/`o;====-    Olga Kryzhanovska   -====;o`\/ }
> .----'-/`-/     [email protected]   \-`\-'----.
>  `'-..-| /       http://twitter.com/fleyta     \ |-..-'`
>       /\/\     Solaris/BSD//C/C++ programmer   /\/\
>       `--`                                      `--`
>
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