[kde-linux] System -> Printing doesn't work.

[Rajko M.]

On Saturday 21 February 2009 11:21:51 am Anne Wilson wrote:
> On Saturday 21 February 2009 16:36:04 Rajko M. wrote:
> > It is not KDE4, or any other DE, that should know.
> >
> > su     root privileges - user that invoked environment
> > su -   root privileges - root environment
> >
> > Note that pesky little dash after command. It is the only difference
> > between mess and "work as expected".
>
> I did check this, Rajko.  Although I would not have done it his way, I did
> try it and it succeeded, so I assume that in this case root's environment
> is not particularly needed.

Hi Anne,

I'm sorry for long post, but your experiment that succeeded is just special 
case where read, write and execute permissions are set to make no practical 
difference between file owner and group, so root:users will work just fine as 
user_name:users, until next time when user forget to use "su" and all of the 
sudden configuration doesn't work. In general it should be avoided, just as 
you do. 

User settings in KDE never need root rights in any form. 
As soon as some configuration module is asking for root password, it is no 
more user setting stored in $HOME/.kde or $HOME/.kde4, but system wide 
setting that will change /etc . 

The problem is that not experienced users often don't understand role of 
administrator login, assuming that when you have root rights it will 
automatically solve any problem. That approach sometimes works, if 
application they use actually change system files in /etc/ directory, and 
sometimes creates mess, if they use application that is changing only user 
settings in $HOME. 

Printer setup is classic example where user have to use both, system setup 
tools, as root, to install drivers and create printer queue(s), and user 
settings tools, as user, to select queue and options available in it. 

While in Windows driver installation runs with installation program that is 
provided on CD and users are very often administrators all the time, in Linux 
your driver installation and setup tool is already installed on hard disk, 
often with bunch of drivers, and users often confuse system setup with user 
setup that is just another program in the same menu, as well as user and root 
role. 

Now, if one doesn't understand difference then it will happen to configure 
root (as user) settings after "su -", or to create root owned files in own 
directory, if they us "su" (including "sudo" on openSUSE default setup), and 
that can have different consequences, from irrelevant, to strange problems: 
- non sticking setup changes, 
- application works only after "su" (sudo) which they would say "it works as 
root", 
- sometimes application will work different depends on current login and user 
will report random changes if he doesn't pay attention what login is used,
- and probably many more strange cases. 

I can't imagine all strange interactions between access rights and file 
ownership, and that is only for classic UNIX type of access rights, with 
introduction of Access Control Lists (ACL) mess can be even more amusing, and 
harder to decipher. 


-- 
Regards, Rajko