I have a directory say PETS, I have two groups CAT, DOG.
CAT has read access to PETS..
DOG has read / write access to PETS.

Can this be done in linux.

As unix/linux uses xxx for permissions, there is only one group that can have access to that directory. Is this a weekness in linux??.

Thanks

Derrick

well no because you have three levels in the system, and seeing as you started it i'll use your analogy:

Owner: Rover
Group: Dogs
Others: Cats

so file with attribs a'la "ls" of say, rwxrwxr-x (or alternatively noted as 775) say that Rover made the file and any other dog can look change it, but anyone who isn't a dog, e.g. a cat can only look at the file.

a weakness?? LINUX IS INVINCIBLE!!!

hmm, funny analogy to bring up right now, as i'm currently burning a divx copy of Cats And Dogs to a cdr Go Lou!

I know LINUX IS INVINCIBLE but I do not want xx4 on my pets directory

well set the correct permissions on it and only a certain group will have access. i'd assume that if a file owner is a memeber of two groups then naturally all members of those two groups would inherit group perms... sounds bloody obvious actually!

Did I forget to mention I am using samba, so that x?x . So at the ? I need to define two groups, one for read and one for read/write.

Help me understand

thanks

erm, can you clarify exactly where this xxx notation has come from? i'm really struggling to see what you're getting at.... the group with read write will be the one in which the owner belongs. all other groups will have the lesser set, whatever you choose them to be...

Ok.
my xxx notation is User / Group/ Other

7 Read, write, exectable
6 Read Write
5 Read only exec
and so on.

I have a directory called /home/PETS/

I have the groups CATs, DOGs

A user from the group Dog makes a new file (touch myfile)

I need all users of the group DOGs to have read / write access to "myfile".

I need all the users from CATs to only have read access to "myfile".

There are five useres in DOGs and five users in CATs.

Tanks

Addition
Others cannot have access

once:
If you want to get multiple user or group permisions you will have tough time setting them up in linux. You are right that this is a weakness of Linux

if you don't know that you can use ACLs (Access Control Lists) and EA (Extended Attributes) which will enable just that

say you have dir /mama you can say
setfacl -m u:joe:rwx -m u:john:rwx ... /mama
then you can play around just like in Win nt/2k/xp

but it's not so trivial to get this working
goto acl.bestbits.at to get all info
but in short
you have to patch kernel, install fileutils, acl, ea utils, compile support for acl and reboot
(very easy and straight forward if you have done it before)

good luck

Hi Noerr De Dykul

Any ideas how this will react with samba. I will definatly look at your sugestions, but just maby you have quick awnser.

Thank you

well yeah you can't specify that fundamentally, but then you can continually go round in ever decreasing circles with more and more demands on what you can and can't do with a file system. *nix file systems still totally trash FAT32 / NTFS. as to how it will relate to sharing over samba.. well why samba? assuming you're going from linux to linux then you should use nfs, and then you'll be back to the same rights issues as for a native file system. I don't think that samba will help at all, probably hinder, but as i don't share any nix drives of samba directly i don't know.

It is a File server for windows clients.

once: it works perfectly well with samba, all you need to do is include support for acl while compiling
to help you there is my configure statement for samba

./configure --prefix=/usr --sysconfdir=/etc/samba --libdir=/etc/samba \
--localstatedir=/var/log/samba --with-smbmount --with-quotas --with-automount \
--with-smbwrapper --with-acl-support --with-ssl

=====
that is a little more than acl support only but works fine and samba gets installed without that /usr/local prefix which bothers me big time

If you are only concerned about this for Samba, then why don't you just specify this in the smb.conf file instead of worrying about it with the directory permissions?

without acl, you have a very tough time to do simple things like

joe can rx my dir , and john can rwx my dir ...