From: yermej <yermej@...>
Date: 2007-11-26T08:25:02+09:00
Subject: Re: Has anyone used File.stat to check permissions

On Nov 25, 4:36 pm, yermej <yer...@gmail.com> wrote:
> On Nov 25, 3:29 pm, Peter Loftus <lof...@gmail.com> wrote:
>
>
>
> > In ruby API there is an example
>
> >  s = File.stat("testfile")
> >    sprintf("%o", s.mode)          #=> "100644"
>
> > I need to check the last three numbers from the octal notation which is
> > "644"
> > which means:
> > rw- for user
> > r-- for group
> > r-- for other
>
> > Does anyone know how i could check just those three numbers and leave
> > the rest
>
> > Regards
> > Loftz
> > --
> > Posted viahttp://www.ruby-forum.com/.
>
> If you're wanting to compare to the String "644":
>
> s.mode.to_s(8)[-3..-1] == "644"
>
> otherwise, you can mask using bitwise & and compare to the Fixnum
> 0644:
>
> (s.mode & 0xFFF) == 0644
> (s.mode & 07777) == 0644
>
> Jeremy

Sorry, those masks will probably work in most cases, but I guess you
should really use 0777 or 0x1FF to only get the ugo fields. Otherwise,
there might be problems if something is setuid or has the sticky bit
set.

Jeremy