What does the minus sign - do?... in the command sudo su -

What does the minus sign - do?... in the command sudo su -

[Don Saklad]

What does the minus sign - do?... in the command

     sudo su -





.

Re: What does the minus sign - do?... in the command sudo su -

[Peter Dyballa]

Am 25.09.2013 um 11:19 schrieb Don Saklad:

> What does the minus sign - do?... in the command
> 
>     sudo su -

(Almost) Nothing. It just opens a shell…

--
Greetings

  Pete

If my theory of relativity is proven successful, Germany will claim me as a German, and France will declare that I am a citizen of the world. Should my theory prove untrue, France will say that I am a German, and Germany will declare that I am a Jew.
				– Albert Einstein, 1929

Re: What does the minus sign - do?... in the command sudo su -

[Pascal J. Bourguignon]

Don Saklad <dsaklad@gnu.org> writes:

> What does the minus sign - do?... in the command
>
>      sudo su -

man su

-- 
__Pascal Bourguignon__
http://www.informatimago.com/

Re: What does the minus sign - do?... in the command sudo su -

[Pascal J. Bourguignon]

Don Saklad <dsaklad@gnu.org> writes:

> What does the minus sign - do?... in the command
>
>      sudo su -

Sorry, this was in emacs:   M-x man RET su RET
(or M-x woman RET su RET if you prefer it).

-- 
__Pascal Bourguignon__
http://www.informatimago.com/

Re: What does the minus sign - do?... in the command sudo su -

[Floyd L. Davidson]

Don Saklad <dsaklad@gnu.org> wrote:
>What does the minus sign - do?... in the command
>
>     sudo su -
>
>.

It should cause you to read the man page for su, where it is explained
as the equivalent of -l or -login.  But you want to read the details
of exactly what that means...

In practice it's the way you select the environment you'll be in after
the su command.  If you want to retain your own login environment, don't
use the -login option.  If you want the environment the specified user
would normally get, use the -login option.

-- 
Floyd L. Davidson           http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)                      floyd@apaflo.com

Re: What does the minus sign - do?... in the command sudo su -

[Kevin Rodgers]

On 9/25/13 3:27 AM, Peter Dyballa wrote:
>
> Am 25.09.2013 um 11:19 schrieb Don Saklad:
>
>> What does the minus sign - do?... in the command
>>
>>      sudo su -
>
> (Almost) Nothing. It just opens a shell…

Actually, it tells su to start a login shell (as opposed to a shell that
inherits the current environment:

      -l      Simulate a full login.  The environment is discarded except for
              HOME, SHELL, PATH, TERM, and USER.  HOME and SHELL are modified
              as above.  USER is set to the target login.  PATH is set to
              ``/bin:/usr/bin''.  TERM is imported from your current environ-
              ment.  The invoked shell is the target login's, and su will
              change directory to the target login's home directory.  This
              option is identical to just passing "-", as in "su -".

`M-x man' is your friend.

-- 
Kevin Rodgers
Denver, Colorado, USA

Re: What does the minus sign - do?... in the command sudo su -

[Kai Grossjohann]

On Wednesday, September 25, 2013 11:19:32 AM UTC+2, Don Saklad wrote:
> What does the minus sign - do?... in the command
> 
>      sudo su -

May I propose to use "sudo -i" instead?  It starts a login shell.

"sudo su -" is similar: sudo starts su which starts a login shell.  I think it makes more sense to have sudo start a login shell, than to have sudo start su which starts a login shell...