Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 2 Mar 2011 19:49:00 -0600 (CST)
From:      Robert Bonomi <bonomi@mail.r-bonomi.com>
To:        demelier.david@gmail.com, freebsd-questions@freebsd.org
Subject:   Re: Question about nethack and setgid
Message-ID:  <201103030149.p231n00R054900@mail.r-bonomi.com>
In-Reply-To: <4D6ECA01.40002@gmail.com>

Next in thread | Previous in thread | Raw E-Mail | Index | Archive | Help

> Date: Wed, 02 Mar 2011 23:51:45 +0100
> From: David Demelier <demelier.david@gmail.com>
> To: freebsd-questions@freebsd.org
> Subject: Question about nethack and setgid
>
> Hello,
>
> I don't understand how nethack can store the score in
> /usr/local/lib/nethack/logfile.
>
> the real binary is here /usr/local/lib/nethack/nethack
>
> And the mode is
>
> -rwxr-sr-x  1 games  games  1793635 25 Jan 2011
> /usr/local/lib/nethack/nethack
>
> So that means people in games group will run nethack as games user (owner 
> of file)

Actually, it means that the program will run with the _group_ id of the
file -- i.e. the 'games' group.  _That_ 's' is the 'sgid' or 'set groupID'
bit.

>         but I'm not in games group ! and I can save the file located in
>
> /usr/local/lib/nethack/logfile which mode is -rw-rw-r--  games  games

Lo and behold!  The file _is_ writable by the games group.

> I'm writing a game that will store file too, because I can't make it 
> works like nethack I was planning using the setuid mode but I don't like 
> much this ..
>
> What am I misunderstanding?

the function of the 'setgid' bit.  <grin.
>
> Cheers,
>
> --
> David Demelier
> _______________________________________________
> freebsd-questions@freebsd.org mailing list 
> http://lists.freebsd.org/mailman/listinfo/freebsd-questions To 
> unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org"
>



Want to link to this message? Use this URL: <http://docs.FreeBSD.org/cgi/mid.cgi?201103030149.p231n00R054900>