Help with groups

[Zebadeous]

I am very new to Linux. Can someone point me in the right direction to find some help?

1. I am having trouble understanding where to find the description of the privileges/authority associated with any defined group. for example, where do I find a the profile defining privileges for Group "user"?

2. There are a number of groups predefined in the Kubuntu release. Are they there for a specific reason?

[JudicatorMX]

Re: Help with groups

1. Open User preferences (they are in system settings if I'm correct). Dialog will show up. You will see all the users. Unlock the dialog, pick a user, select "Properties" (I might have forgotten something as I decided to work in Gnome, not KDE). Then a new dialog will appear where you'll be able to set privileges and manage group for that particular user.

2. Have no idea... I'm noob too

[GreyGeek]

Re: Help with groups

...
2. There are a number of groups predefined in the Kubuntu release. Are they there for a specific reason?

YES!

Groups between 0 (root) and 999 are system groups. Your group is 1000 (IF you were the one to install Kubuntu and have sudo permission) and group 65534 is "nogroup".

If your system is set up for multiple users via either a LAN or remote login and you want to give one or more of them the same permissions you have then add them to your group. If you want to give someone the same permissions as root (which I'd never do) add them to root's group.

Some groups are related to system devices and functions. If you or someone can't use the CDROM then add them to the CDROM group. Generally, when you add or remove applications the app install usually takes care of the group stuff. I've been using Linux for 11 years and for the last five years I haven't had to add, delete or modify any groups.

You can see what groups you are in by issuing
groups
from a console, or, you can click on KGear-->System-->KUser and Kuser will open a dialog which will allow you to add, delete or modify any user or group. BE CAREFUL!! You can bork your system by accident or ignorance.

[Zebadeous]

Re: Help with groups

Thanks for taking time to respond to my forum question. I am a mainframe dinosaur trying to find my way into the brave new world.

I am trying to add a user account that has only limited authority. I can see the various groups and add users, but I do not know how to find the "definition" of access/authority allowed a particular group.

Thanks if you can help

[GreyGeek]

Re: Help with groups

You might find Paul Sheer's book on Linux Administration helpful. The link to the HTML pages is here: http://rute.2038bug.com/node14.html.gz
but on that page is a link to a downloadable PDF file, too.

Section 11.0 states:

"Other than the superuser, every other user has limited access to files and directories. Always use your machine as a normal user. Log in as root only to do system administration. This practice will save you from the destructive power that the root user has. In this chapter we show how to manually and automatically create new users.

Users are also divided into sets, called groups. A user can belong to several
groups and there can be as many groups on the system as you like. Each group is
defined by a list of users that are part of that set. In addition, each user may have a
group of the same name (as the user’s login name), to which only that user belongs.

11.1 File Ownerships

Each file on a system is owned by a particular user and also owned by a particular group. When you run ls -al, you can see the user that owns the file in the third column and the group that owns the file in the fourth column (these will often be identical, indicating that the file's group is a group to which only the user belongs). To change the ownership of the file, simply use the chown, change ownerships, command as follows.


chown <user>[:<group>] <filename>"



Since EVERTHING in Linux is a file, including devices, drivers, directories, applications, bash scripts, etc..., one can make them "owned" by a specific group, even one of your own making.

The rest of Chapter 11 in "Rute" goes on to explain what you need to know, so I won't copy any more of it here. By the way, The Rute manual is 8 years old. While "most" of the basic command line stuff is valid, the architecture of today's distros is different, especially in how some of them boot via the initab file, the structure of the /etc directory and its sub directories, etc... So, don't be surprised if some of what he writes doesn't seem to fit. If you have any questions we'll be here!