CentOS - Mar 2011 - Default permissions for creating a new user

I know this is a Linux 101 question, however I am unable to 
locate the answer in my O'Reilly Linux book: how to set the 
default for permissions when creating a new user.  The default 
for the GUI in my newly installed Centos 5.5 is 700.  I usually 
use 774.

And when root creates a new directory, is there a way to have a 
default there too?

Lastly, if root or someone with root privileges creates a 
sub-directory, is there a setting so that the sub-directory will 
have the owner/group and permissions as the parent directory?


Todd

-- 
Ariste Software
Petaluma, CA 94952

http://www.aristesoftware.com

On 03/25/11 4:45 PM, Todd Cary wrote:
> I know this is a Linux 101 question, however I am unable to
> locate the answer in my O'Reilly Linux book: how to set the
> default for permissions when creating a new user.  The default
> for the GUI in my newly installed Centos 5.5 is 700.  I usually
> use 774.
>
> And when root creates a new directory, is there a way to have a
> default there too?
man useradd
man umask

on 16:45 Fri 25 Mar, Todd Cary (todd at aristesoftware.com)
wrote:
> I know this is a Linux 101 question, however I am unable to 
> locate the answer in my O'Reilly Linux book: how to set the 
> default for permissions when creating a new user.  The default 
> for the GUI in my newly installed Centos 5.5 is 700.  I usually 
> use 774.
> 
> And when root creates a new directory, is there a way to have a 
> default there too?
> 
> Lastly, if root or someone with root privileges creates a 
> sub-directory, is there a setting so that the sub-directory will 
> have the owner/group and permissions as the parent directory?
man adduser -> FILES -> /etc/login.defs

At login, umask is set by the shell initialization.  Check ~/.bashrc,
~/.bash_profile, /etc/bashrc, and /etc/profile, for the usual suspects.

-- 
Dr. Ed Morbius, Chief Scientist /            |
  Robot Wrangler / Staff Psychologist        | When you seek unlimited power
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On Fri, Mar 25, 2011 at 7:45 PM, Todd Cary <todd at aristesoftware.com>
wrote:
> I know this is a Linux 101 question, however I am unable to
> locate the answer in my O'Reilly Linux book: how to set the
> default for permissions when creating a new user. ?The default
> for the GUI in my newly installed Centos 5.5 is 700. ?I usually
> use 774.
It's a user shell default setting, overridable with the "umask"
setting.
> And when root creates a new directory, is there a way to have a
> default there too?
Yes, reset the "umask" in root's /root/.profile for default login
behavior. Getting it into non-login behavior may take a bit more work,
and you may have to review and think about what your sudo settings do
if you use sudo.
> Lastly, if root or someone with root privileges creates a
> sub-directory, is there a setting so that the sub-directory will
> have the owner/group and permissions as the parent directory?
Please look into the "sgid" settings with the "chmod"
command. And be
aware that, if a user can write a file, they can reset its permissions
unless you get *very* arcane with things like NFSv4 ACL's.