Having access privilege problems in Ubuntu.

[fuzzybabybunny]

I'm a first time Linux user and I'm kinda confused.

A week ago I could copy files, make folders, do all the basic admin stuff in Ubuntu, but now all of a sudden I can't. I keep getting the error "You do not have permissions to write to this folder" or somesuch.

Under users and groups I'm under the Admin group. Why would it suddenly decide to lock me out?

 

[cleverhandle]

Being in the Admin group doesn't mean that you automatically have admin powers all the time - you have to specifically request them. (This is a good thing.) In Ubuntu, you do this by prefixing a command with "sudo". If you're using a graphical file manager, I'm not sure what Ubuntu does, but there's probably a separate application menu entry that would say "File Manager (Administrative)" or something similar. Or maybe there's some menu within the file manager that elevates your privileges. The idea being that if you just open a file manager as usual, then it's running with your normal user privileges, which won't let you creates files and folders in system locations. If you can't find the Ubuntu-proper way to do it, running sudo nautilus --no-desktop from a terminal prompt should also work.

BTW, this should be in the OS forum, though a lot of the people there check this forum as well.

 

[xtknight]

Actually, Ubuntu doesn't have a shortcut for "gksudo nautilus", aka, file manager with su priv. I'm actually not even sure what 'admin' is, but it isn't super user and it doesn't allow you super user privileges.

In Unix, the philosophy is that one group owns a file. If you're not from that group then generally you can't write or delete anything made by that group. Of course there are ways to make it so other groups can modify/delete the stuff, but the best thing to do is just to stick to your user group.

I will assume your regular user name on the box is 'fuzzybabybunny'. I think you changed your user from the 'fuzzybabybunny' group to the 'admin' group, and then lost your ownership privileges. What you need to do is change that back, preferably as soon as possible.

At the top, click on System --> Administration --> Users and Groups. In the list that comes up, click properties on 'fuzzybabybunny' and go to the advanced tab. Now set main group to 'fuzzybabybunny' instead of 'admin'. Click OK to get out of the dialogs. Now reboot. Now you should be able to use and control your files like normal. If you created any files while you were under admin, I can tell you how to change ownership to 'fuzzybabybunny' as well.

You shouldn't need super user overly often. You can elevate your self by entering a password. When you try to change system settings or install software it asks so it can elevate you to super-user for that program. Once you enter your password, you have free super-user elevation for a while and then lose it again and must re-enter the password. Don't worry, you still have complete control of your PC. It's just that doing everything as super user (root) is rather insecure.

 

[n0cmonkey]

The admin group probably lets you use sudo in ubuntu, and since root is disabled (or was) this is important.

 

[xtknight]

Originally posted by: n0cmonkey
The admin group probably lets you use sudo in ubuntu, and since root is disabled (or was) this is important.

Yeah. Do keep yourself in the admin group, but it shouldn't be your main group. You are still in lots of other groups at the same time.

 

[cleverhandle]

Originally posted by: xtknight
I will assume your regular user name on the box is 'fuzzybabybunny'. I think you changed your user from the 'fuzzybabybunny' group to the 'admin' group, and then lost your ownership privileges.

No - even if he (she?) changed his group, his username is the same. He would still be able to read/write to his home directory. Files are created owned by your username, no matter what your primary group is. Play around with the newgrp command if you want to test it out.