Subject: Re: group perms
To: Malcolm Herbert <mjch@mjch.net>
From: Hauke Fath <hf@spg.tu-darmstadt.de>
List: netbsd-users
Date: 05/17/2006 13:15:29
Am 17.05.2006 um 11:53 Uhr +1000 schrieb Malcolm Herbert:
>I have the situation where I have created a group of users in /etc/group
>and want them to all be able to read/write/destroy each others' files in
>the directory set aside for them.

I see two issues here.

One is that you need to get users to create files group-writable. 
'umask 002' would be a way to do this, but some security-sensitive 
applications start to bitch when directories and files are writable 
by any other than the owner.

Some Linux based OSes stick every user in a primary group of her own, 
and then use umask 002 in an attempt to make group work easier.

>I seem to recall that some flavours of Un*x allow permissions to be
>set on a directory in such a way that group rights are inherited by
>files created by other members of a group in that directory, but I can't
>remember the magic to get that working ... any ideas?

That's the sticky bit on directory permissions for System V derived 
Unices (Solaris, also Linux). The BSD way is to give any new files 
the gid of the enclosing directory per default, i.e. what most people 
want.

>For some reason I am thinking that the sticky bit might be the key,

Not on BSD. There was discussion a while back about having a mount(8) 
option for SysV behaviour, but I don't know what came of it. Things 
may also be different for network mounts.

	hauke

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