All about Unix groups and access control.

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3
votes
3answers
3k views

Reset all groups to default

I recently set up some groups and users on my machine, and now I want to remove all those users and all those groups. Somewhat stupidly, I read on an Ubuntu forum or something like that that it was ...
6
votes
2answers
7k views

Add all users in one group to another group?

I have some users in a group called aa and I need to give them the rights to write to a folder which is currently tomcat:tomcatdeploy. The straightforward way to do this is to add all the users to ...
10
votes
2answers
4k views

I can't delete a file that I have write permissions for as a group member

$ touch testfile $ chmod g+w testfile $ sudo adduser user2 user1 $ stat -c'%a %A' testfile 664 -rw-rw-r-- $ su user2 Password: $ groups user2 user1 $ rm testfile rm: cannot remove `testfile': ...
2
votes
3answers
239 views

How to make files created by a specific user to have specific permissions by default

Here's a sequence of commands and the resulting output: $ touch testfile $ stat -c'%a %A' testfile 644 -rw-r--r-- What must I do so that when a user follows that sequence, I get this output ...
6
votes
2answers
7k views

I added a user to a group, but group permissions on files still have no effect

I changed permissions of a file (chmod g+w testfile) and running ls -l testfile gives: -rwxrwxr-x 1 user1 user1 0 2011-01-24 20:36 testfile I then added a user to that group ("/etc/group" has ...
3
votes
1answer
1k views

Adding kill to a sudoers group

How can I give permissions in sudoers such that each member of a group is able to kill the process owned by another member of the group? Scenario: I have two users -- bill and dev-cron -- who are ...
11
votes
2answers
9k views

Why is Debian not creating the 'wheel' group by default?

It appears to be Unix tradition that a wheel group is created automatically, but Debian (and children, naturally) doesn't do so. Is there a rationale somewhere? Where else have you seen this tradition ...
10
votes
1answer
8k views

Meaning of root:wheel

What does root:wheel mean in the following? chown root:wheel myfile
95
votes
6answers
29k views

Where did the “wheel” group get its name?

The wheel group on *nix computers typically refers to the group with some sort of root-like access. I've heard that on some *nixes it's the group of users with the right to run su, but on Linux that ...
6
votes
5answers
262 views

Changing Unix group for files

I have a file that a colleague and I are editing together, on a Unix system. We are using Unix group permissions to edit it. We have one Unix group that we are both members of. Whenever I save the ...