libc regex word-boundary support fallen-off?

Carl Johnson carlj at
Fri Mar 9 04:41:38 UTC 2012

RW <rwmaillists at> writes:

> I've noticed for some time that claws-mail and less (which I think use
> libc's regex(3)) don't support word boundaries in searches. I might be
> delusional, but I think I've used \b in the past in both of those
> applications in FreeBSD.  
> According to regex(3) it's an implementation POSIX.2, so the feature
> needn't be supported, but at the bottom of the page it says
> "word-boundary matching is a bit of a kludge", so presumably it has
> been.
> Does anyone know what's going on?
> I switched from i386 to amd64 last year so it might be something to do
> with that. I'm currently using 8.2p6.

The only way I have found to do it is [[:<:]] and [[:>:]].  That is very
awkward, so I't love to hear of a shorter way.  I found them in the
re_format(7) manpage.
Carl Johnson		carlj at

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