Date: Wed, 10 Feb 2010 19:42:31 +0100 From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no> To: Garrett Cooper <yanefbsd@gmail.com> Cc: Andrew Brampton <brampton+freebsd@gmail.com>, freebsd-hackers@freebsd.org Subject: Re: sysctl with regex? Message-ID: <868wb1hqzs.fsf@ds4.des.no> In-Reply-To: <7d6fde3d1002100923i6bbc24a7ocaf408f4d78ec59f@mail.gmail.com> (Garrett Cooper's message of "Wed, 10 Feb 2010 09:23:01 -0800") References: <d41814901002091308s7e894b55p880bde165bbbe703@mail.gmail.com> <86tytqvwky.fsf@ds4.des.no> <d41814901002091528i4884987cmb7347dfe4d50bdc5@mail.gmail.com> <26049703-8844-4476-B277-776A4EFC0A53@gmail.com> <86fx59jpti.fsf@ds4.des.no> <7d6fde3d1002100923i6bbc24a7ocaf408f4d78ec59f@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Garrett Cooper <yanefbsd@gmail.com> writes:
> Dag-Erling Sm=C3=B8rgrav <des@des.no> writes:
> > A glob pattern can be trivially translated to a regular expression, but
> > not the other way around. =C2=A0Basically, * in a glob pattern correspo=
nds to
> > [^/]*, ? corresponds to ., and [abcd] and [^abcd] have the same meaning
> ^^^^ ???? ^^^^
> The former is a positive assertion, where the latter is a negative
> assertion -- how can they have the same meaning?
Read the entire sentence. BTW, neither of these are assertions, and
neither of these is negative in any sense, they are just different ways
of selecting characters from the alphabet (in the extended sense).
> > as in a regular expression. =C2=A0The glob pattern syntax has no equiva=
lent
> > for +, ?, {m,n}, (foo|bar), etc.
>
> +, {}, and () -- no... that's typically an extension to shell expanded
> values (IIRC). ?
I can't make sense of this - I'm not sure whether you misunderstood what
I wrote, or just failed to express yourself clearly...
> > Finally, .* and .+ are *both* greedy. =C2=A0Perl's regular expression s=
yntax
> > includes non-greedy variants for both (.*? and .+? respectively).
> Yes, but I didn't explicitly note those forms.
No, but you claimed that .+ is not non-greedy, which is incorrect.
DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?868wb1hqzs.fsf>