Anything related with user accounts and user management on Unix-like systems.

learn more… | top users | synonyms

4
votes
1answer
2k views

How can a user run a program in kernel mode?

Is it possible for a user to run their own program in kernel mode? How could a user accomplish this? What weakness in the system's protection mechanism would they have to bypass? I'm thinking that a ...
4
votes
2answers
4k views

SSH not landing in the home directory

I have recently installed Raspbian into a Raspberry Pi. As part of the installation process I changed the user name and group from the default (pi) to my own (let's call it user) using usermod and ...
4
votes
2answers
4k views

'mysql' user and group creation, ownership settings

I know what the linux command chown does, I used it to change the ownership or group of a file. If there is a MySQL installation on a Ubuntu machine, I saw some people doing the following thing: ...
4
votes
1answer
197 views

How do you give a developer group access to apache, MySQL, php and the webroot?

We have 3 web designers that are currently logging in to our server via root to configure apache and setup websites. I have very basic linux knowledge (I'm a web designer) and have created users and ...
4
votes
1answer
173 views

Where are passwords stored and how are they encrypted in OS X?

I know that on a Linux system passwords are stored in /etc/shadow and are salted and encrypted using a one way hashing algorithm like MD5, SHA-256 or SHA-512. It looks like there is no /etc/shadow ...
4
votes
2answers
1k views

recommended procedure to create a user/group during RPM install

after trying hard to search for RPM best practices guides and finding virtually none, to my surprise, I resort to the community - I need to ensure that some users and groups exist after the ...
4
votes
1answer
568 views

Force pubkey-auth user to set password at first login

When I create a new user account I ask users to send me a public key, and want to force users to set the password the first time they log in with keypair authentication. If I create an account with an ...
4
votes
3answers
972 views

Permanently switching to zsh in a script, without being root and without being asked for the password

Is there any way to run chsh -s /bin/zsh without being root and without being asked for the password? I want to put it into a non-interactive script that isn't called by root.
3
votes
4answers
9k views

What command should I run after making changes to /etc/passwd file

I have made some changes to /etc/passwd file ,now I wanted to see if the effect of changes taken place or not .What command should I run for that. For example after making change to ...
3
votes
1answer
202 views

Enable superuser when logged in with another user

Suppose that the machine has two users: Alice (admin) Bob (standard user) While Bob is logged in, how can Alice modify a root file (Bob does not have this permission even with sudo)? Alice tried: ...
3
votes
2answers
7k views

change root account username

In windows it is possible to change administrator username for security reasons. Is it possible to change root username in Linux too?
3
votes
6answers
3k views

sort ls output by users

On Linux, is there a way to sort ls output by users? What I try to achieve is something like this: user_a   file1 user_a   file2 user_b   another_file user_c   this_file user_c ...
3
votes
5answers
25k views

What is the command for listing all users who are members of the admin group?

I am looking for the name of the superusers list on Fedora. (On Ubuntu is seems to be "sudo".) I want to add one of the users to the superusers list. The groups command only lists the groups of the ...
3
votes
2answers
542 views

How to Find UID, GID, and any groups I belong to?

How to Find UID, GID, and any groups I belong to ?
3
votes
3answers
2k views

Killing other user processes

There are certain user environments in which we have to login during certain performance testing and and kill all the process running in that environment. The environment names are like rswrk01, … up ...
3
votes
3answers
322 views

Why only one active group at a time?

As far as I understand the users in Unix system can belong to multiple groups and one of them will become the primary group for that user. Others will be supplementary groups. All of this User/Group ...
3
votes
3answers
7k views

Why is file ownership inconsistent between two systems mounting the same NFS share?

I have one IBM AIX server (serverA) which is connected to the san storage. I have created a volume group and also file system (jfs2) and mounted to directory /profit. After that I created a NFS ...
3
votes
3answers
392 views

How to switch back and forth between users quickly on a single terminal?

I'd like to switch to another user without logging out the first user, then log in as a third user without logging out the other two, and so on, then switch between all users quickly. I'd like to ...
3
votes
1answer
83 views

Does root not require a password to log in as a user?

Does root not require a password to log in as a user even though a password has been set for that user? When I am logged in as "root", su user logs me in as "user". There is no prompt for a password. ...
3
votes
2answers
11k views

su - user doesn't work for users without a password

I've created a user on CentOS with useradd -M username. Now, I want to become that user just like su - username. It asks me for a password for that user but I didn't set a password for that user. As ...
3
votes
2answers
210 views

Unix command to find files read by specific user

I would like to find files accessed by specific user (even just read) within a folder tree. I thought the find command had this option, but it actually just searches for owner user. Is there any other ...
3
votes
4answers
3k views

How to configure permissions to allow file access?

I'm running Wowza Media Server on my server as "root". The problem is that all files created (recorded) by Wowza are "root:root" and aren't writable, editable, or deletable by any other users. How can ...
3
votes
3answers
30k views

How do I know a specified user's permissions on Linux with root access?

I have root access to my local server. And some days ago my colleague created a user on that server, giving me the uesrname and password. But the user has a minimized permissions. Like the user can't ...
3
votes
2answers
7k views

How can I have a separate umask for directory or user?

I want a separate umask for a directory or a user. How can I do this? Edit: I am using Debian 6. The reason why I want to do this is, I want all my SFTP users to create files with write on group. ...
3
votes
1answer
176 views

Default files in home dir for each user

I'm using ubuntu server 14.04. I want to add some files and folders by default in each user's home directory, whenever a user account is created.
3
votes
1answer
192 views

Two users with different permissions on same directory

Is it possible to give two users different permissions on the same directory? I want to use it for ftp: userFull gets R+W and userLim gets only Read, depending on who logs on. Im getting stuck on the ...
3
votes
1answer
315 views

Is running programs as another user useful?

After watching a talk by Douglas Crockford on security where he talks about how browsers got the right answer to the question "Who's interest does the program represent?", I wondered if it was ...
3
votes
1answer
1k views

Is there a way to find out how many instances of the root user are logged into a Linux machine?

We have a handful of users that login to our Linux virtual machine as root either through the vSphere client or through SSH and I want to see if there is a way to tell if multiple root users are ...
3
votes
1answer
3k views

Difference between passwd and passwd- file [duplicate]

Possible Duplicate: Who creates /etc/{group,gshadow,passwd,shadow}-? I have a strange passwd- file in /etc, notice the trailing dash: root@ubuntu:~# ls /etc/passw* /etc/passwd ...
3
votes
2answers
253 views

Execute command on shared account login

At work our team uses a shared account "appadmin" to administer our application. At login, each one of us sources an "aliasrc" file containing his or her preferences. (aliases, display, prompt, ...). ...
3
votes
1answer
268 views

Duplicate a user, or at least the password

I have some application that needs to create users that have the same password as others. Is there a way to do this without having to edit the /etc/shadow manually? Some sort of command?
3
votes
3answers
88 views

Understanding a couple of points regarding root privileges

I just wanted to confirm my understanding of a couple of things related to root privileges. Is it correct that: The user name "administrator" is not a reserved name with implied privileges, it is ...
3
votes
2answers
747 views

Preserve ownership with rsync and nonexistent user

I have two computers with the same user, me@Home and me@Work. I usually kept their folders synced by bringing Work home (it's a laptop) and rsyncing over LAN. However, now I'm not bringing Work home ...
3
votes
1answer
168 views

Gives access to root user for a period of time

I want to know if it's possible to give access to root user for one week or a month, for example. It's possible to increase the period of time before the defined period ends? Is it possible to give ...
3
votes
2answers
487 views

How to open a program as another user inside a logged display?

I'm trying to open netbeans as a different user, but isn't working. I'm running a Kubuntu 12.04 LTS with KDE. And I tried the following: Open a terminal, type su - myotheruser, type the myotheruser ...
3
votes
2answers
1k views

PHP interface to manage linux user accounts

I have a linux web & samba server. I need to give administrators access to manage minor accounts & groups. Is there a secure php web interface that can do this? I don't want to give them shell ...
3
votes
3answers
260 views

sudoer file how to give a particular user full access to only certain file

I want to give a user full access to only certain files, can someone show me how to do that? For example, I want to modify the sudoer file to grant user access to only certain file. Thanks.
3
votes
1answer
45 views

Are there any user guaranteed to exist on the system

Beside the root (which I guess IS guaranteed), is there any other username guaranteed to exist on Unix system? Linux system? Fixed UIDs for those users? If not guaraneed, are there at least any ...
3
votes
1answer
2k views

/home/user: change directory failed error

I just installed Arch reading from the Beginners' Guide on the Arch Wiki. Once I rebooted Arch, I logged into root then I added my own personal account: useradd fox then passwd fox and set my password ...
3
votes
2answers
1k views

talkd doesn't print a message

I wanted to use talk with my brother (we both have Debian jessie). So i installed inetutils-inetd, inetutils-talk, and inetutils-talkd. Now i wanted to try wether it works. So i created a testuser ...
3
votes
2answers
64 views

Why does “logging out” of a session activate a newly added supplementary group? [duplicate]

I asked the following question Added user supplementary group, but 'groups(1)' not showing change earlier today. Now I'd like to know why the answer works. After running adduser user group ...
3
votes
1answer
4k views

file system uid and gid in linux

I came across a linux kernel tutorial and there they talked about 4 pairs of identifiers and one of them was file system uid and gid. Could someone explain me what it is and how it is different from ...
3
votes
2answers
5k views

New user can't login in Linux Mint

I have created a new user in Linux Mint 12 with these commands: sudo useradd irene sudo passwd irene //Here I entered the password But if I try to login with this user, the screen goes black for a ...
3
votes
1answer
3k views

User logged in by sftp does not show up in `w`

My server is Centos 5. I have a chroot environment set up with the following in my sshd_config Match group sftponly ForceCommand internal-sftp ChrootDirectory %h AllowTcpForwarding no ...
3
votes
2answers
7k views

smbpasswd failed for new Samba install on fresh Ubuntu 11.04

I've installed Samba on a fresh Ubuntu install. I run the command sudo smbpasswd -a someuser New SMB password: Retype new SMB password: Failed to add entry for user someuser. I've read that you ...
3
votes
2answers
969 views

In new users's home directory create sub-directory with a specific group and permissions

Linux will copy the the contents of /etc/skel when a new user is created. I want to have a sub-directory in each user's home directory, MyStevedore. I want this directory to have the owner be the new ...
3
votes
1answer
785 views

Set visible directories for SFTP access?

I am setting up SFTP access to one of my machines running Linux with the Dropbear SSH server. When I SFTP onto the machine remotely, I can see the entire filesystem on it, even if I might not have ...
3
votes
1answer
39 views

What is the purpose of the 'ssh' group?

There is a system user named sshd on my system, and a group named ssh: $ cat /etc/passwd | grep ssh sshd:x:120:65534::/var/run/sshd:/usr/sbin/nologin $ cat /etc/group | grep ssh ssh:x:117: My guess ...
3
votes
1answer
45 views

Hyphen's availability in UNIX username

It is said that in UNIX and other alike systems, we can use hyphen for username in addition to Latin characters, numerics and underscore. On the other hand, the hyphen character is used as operator in ...
3
votes
1answer
72 views

Access a file in PHP through a symbolic link from a user that normally doesn't have permission

I have this website, where if the user submits a form, a python script is executed through a php page, and the python script creates a zip file and should offer it to the user for download through a ...