Arch Linux

tntcoda

Member

Registered: 2007-07-24

Posts: 115

File Permissions Query / Linux Access Control

Hi,

Lets say I am user: bob in group: users.

There is this file:
-rw----r-- 1 root users 4 May 8 22:34 testfile

First question, why can't bob read the file as it's readable under others? Is it simply that if you are denied by group, then you are auto-blacklisted for others? I always assumed that the final 3 bits took precedence over user/group permission bits, guess I was wrong...

Second question, how is this implemented? i.e how does this work in relation to Access Control, is it related to how ACLs work / are queried? Just trying to understand how these 9 permission bits are actually implemented/used in Linux. Maybe it's just a simple procedural comparison through each group of 3 bits and denies on the first fail?

Thanks,

Jack

sand_man

Member

From: Australia

Registered: 2008-06-10

Posts: 2,164

Re: File Permissions Query / Linux Access Control

Not too sure but my guess is that "others" is referring to groups that are not "users". Bob is in the users group which has no access so doesn't qualify to be classed as "others".

OMG I'm so terrible at explaining things...

Last edited by sand_man (2010-05-10 01:29:15)

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tntcoda

Member

Registered: 2007-07-24

Posts: 115

Re: File Permissions Query / Linux Access Control

Not too sure but my guess is that "others" is referring to groups that are not "users". Bob is in the users group which has no access so doesn't qualify to be classed as "others".

OMG I'm so terrible at explaining things...

Thanks, I suppose it makes sense that group and others should be mutually exclusive.