tty permissions (was Users and Groups)

[Karl Larsen]

Mikkel L. Ellertson wrote:
> Tim wrote:
>   
>> Just out of curiousity, I did a "ll /dev/tty*" and saw a strange mixture
>> of ownership:
>>
>>     
> <----------------------------[ SNIP ]--------------------------->
>
>   
>> Various "tty"s were owned by root:tty if they had a double-digit number,
>> or root:root if otherwise.  The "ttyS"s were owned by root:uucp (this
>> box only has one or two serial ports - one's external, and I can't
>> remember if there is an internal one).
>>
>> I know tty and ttyS aren't the same thing, but it seems an odd mixture.
>>
>>     
> A big part of it is that there are programs that are using
> /dev/tty[0-7] and /dev/tty. These are the different virtual
> consoles. Normally, if no-one if logged in, tty1 through tty6 have
> mingetty running on them, running as root. In run level 5, tty7
> normally will have a display manager running until someone logs in.
>
> Try doing a command line login as a normal user, and look at the tty
> that matched the VT number. It will be owned by that user that just
> logged in. If you change the number of command line logins, or have
> more then one X secession running, you will change the
> ownership/permissions on a different number of the ttys. Ownership
> can also be changed because they are being used by other programs. I
> like to use a couple of ttys to display different outputs of
> syslogd. They can also be handy to display the error output of a
> program under test.
>
> Now, as you noted, the /dev/ttyS* are different. These are physical
> serial ports, not virtual ports. (Though there may be more device
> entries then there are physical ports.) Exactly how the permissions
> are set depends on the version of Fedora, and how you have
> console.perms set. If you desire, you can set a serial port to be
> owned by the person logged into the console.
How do you do that? I had to join the uucp Group to use /dev/ttyS0 so I 
would like to know a simple way to change owner from root to karl.

Karl




>  It is also possible to
> have a symlink to a serial port and have the symlink managed by
> console.perms.
>
> Mikkel
>   


-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.
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