How to get to "know" kubuntu - like you get to "know" linux?

[LowSky]

1) Why did they broke root account and changed sudo?
2) Why does sudo (something gui like) should not work?
3) Why does this application autoruns if its not in autostart?
4) Where does this application store its configs so i can tweak them manually?
5) Why is this not remembering my settings?

1) root isn't broken, it is disable by default. The consensus among most Linux users, Sudo is a much better idea when you use a GUI based version of a Linux based operating system. This way the user is less likely to corrupt a setting.
2) Sorry I don't understand the question
3) Depending on the Distrobution of Linux this file can be in other place, for Ubuntu, it is /etc/rc2.d
4) Which application? KDE? What do you wish to tweak?
5)What is not remembering your settings?

[Istrebitel]

2LowSky,
the point was i was looking for a way to learn how to answer my questions! Not that i seek particular answers. I see now that q1 and q2 had an answer but the point was, i wasnt looking for answers, but a way to answer them. Not the fish, but the fishing pole.

For example,
4)
I want to be able to find where ANY application i just know the name of stores its configs.

Windows example: if i want to find where application stores its configs, i would look in:
a) registry under software/manufacturer/appname
b) application-rleated folders in my user folder, looking for app name
c) application folder
d) google "where does ***.exe stores its settings"
e) search registry for app name
f) change something in the application, then search for files that have changed recently on my pc
etc

I want to be able to do something like that in linux. Not rely solely on asking forums for someone who stumbled upon same task and found answer, but get the philosophy, get the tendency, get how it's done in linux, so i can solve problems myself.

What i am looking for is a guide that lets you study system's internals. Because otherwise you can only be a slave of manuals and forums. And you will "get" it only after years of working with the system, when similarities will become clear to you.

Thanks to gdonwallace for guide names i will check them out.

Thanks to ankspo71 for trying to answer. I almost got it with graphical sudo.
If i sudo appname, then appname has root owner and can access files at root access level, right?
If i graphicsudo appname, then appname has my_user owner... but how does it then accesses files that my user has no access to?
Does it run a setuid process that then accesses files for it? If it does - what prevents appname without graphicsudo to run same setuid process? I dont understand the mechanism of root elevation in this case.
> kdesudo kate
kate is not ran as root, but as my_user
now how does kate write to a file that is chmod 0700 and owned by root root?

[ankspo71]

Hi Again,
I wasn't sure if I wrote my last reply in the best way possible so I'll try again.
Gksudo and kdesudo will use the current user's application settings rather than use root's application settings, thus preventing sudo from writing root permissions to the user's application settings or other settings in the user's home folder (or write current user permissions in system directories). 95% of the time using a graphical application with sudo safe to do, but the other 5% of the time it could lock up the application (or an entire user account, it has been said) by applying root permissions to files and folders where the user's permissions are supposed belong (and vice versa). In other words... sudo doesn't know that a regular user is running the application, because it always assumes sudo 'equals root user', so we have to tell it "hey I'm a regular user, don't lock me out" by using gksudo or kdesudo.
Hope that clears it up a bit more.

[Istrebitel]

I see, so if i understand that correctly, the program ran by sudo can make its config files owned by root (instead of my user) and subsequent launch will only be possible with sudo because without sudo it wont be able to access config file?

Okay i've experimented with ps and i see that both sudo and gksudo are running program as root. Do you know it more specific how does it work that program is told to use user settings instead of root's? I mean how exactly does it happen.

[QIII]

Just as an aside...

When you are starting to get into the nitty gritty, you are inevitably going to break something. Count on it. Sometimes you may want to break something just to find out what happens and how to avoid or correct the problem you just created. ("Destructive testing" in engineering parlance.)

Nothing worse than an "Aw, crap!" with your daily-use machine.

It would not be unwise to dual boot and have one production version you don't fool with and another you can break and fix at your leisure. That, or drag an old POS clunker out of the garage and do your tinkering on that machine.

[ankspo71]

Hi,
I don't have any examples, but this Ubuntu documentation shows an example of how it prevents problems:
https://help.ubuntu.com/community/Ro...aphical%20sudo
The above example is for Xauthority

An example of breakage is ICEauthority, as seen here:
http://www.psychocats.net/ubuntu/graphicalsudo

Here's a man page with a brief description on gksudo
http://linux.die.net/man/1/gksudo

I think I locked up my gvfs once (it couldn't be stat'ed if I remember right) after using nautilus as root (sudo). That was a long time ago though.

PS. Permission problems can end up being a very bad thing, and in some cases it might not be easily recoverable. It's best to stick to gksudo/kdesudo.

[Istrebitel]

I see. All that happens (As far as community page author knows) is that it moves files to emulate environment. Okay i see it. Thanks again

I understand about breakage. I record every successfull change to the system and i have home on separate partition. If i break this system i'll install from scratch and apply changes i did (i hope i wont destroy /home...) Also i followed advice and partitioned extra 10gb of space for experimental system, so i can install new linuxthere and tell it to be mount as root instead of my current root, therefore i can always roll back to the old one.

[jarviser]

... (i hope i wont destroy /home...)....

Obviously back up the /home directory including hidden (.) files (Ctrl-H when viewing),

but also select the manual partitioning option on install, and when you tell it to mount the partition to /home make sure the Format box is NOT checked and select the same filesystem (ext3 or 4 ) as currently in use.

For a VERY clean reinstall I delete all my hidden files and folders in /home just before reinstall. That's radical suggestion and many would say that loses the configurations, but sometimes that is what is messing with the settings.

When getting to know a new distro I usually re-install like this at least twice after playing around with settings. (3rd time's lucky)