su is a utility to run a shell or other command as another user (root by default).

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1
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1answer
430 views

Combined su and screen at startup

I want to start a long running custom script at boot. The script must run under a specific username. So far I have successfully used the screen command and switched to the user in the custom script. ...
3
votes
1answer
159 views

On OS X, how do I log in interactively as root starting from my normal user account?

I have been doing this for a while: sudo su - but it uses 'sh' rather than 'bash', which is what I'd like to do. Which command will log me in as root and get me a bash shell even if that's not the ...
9
votes
4answers
2k views

su does not change user but does not respond with an error either

While logged in as root I would like to su to a specific regular user. I run su username and immediately receive the prompt back, still as root. There is no error given. I'm aware of the old "the user ...
1
vote
1answer
507 views

How to invoke root privileges from a password prompt of “Software Update” window?

When I try to install software updates using the "Software Update" GUI, I am asked for the root password. Although, I can 'su' in a terminal, the password is not recognized as correct in the GUI ...
16
votes
2answers
7k views

su vs sudo -s vs sudo bash

What is the difference between the following commands: su sudo -s sudo bash I know for su I need to know the root password, and for sudo I have to be in the sudoers file, but once executed what is ...
1
vote
1answer
1k views

Run expect inside a bash script as another user

I am writing a bash script to install some small software I'm developing. That script is run with sudo (as root), but some of the commands that are executed by the script need (or should be) run with ...
0
votes
4answers
7k views

Is there a difference between sudo su - root and sudo -u root -H /bin/bash?

Like title says, is there a difference between these two commands : sudo su - root sudo -u root -H /bin/bash I'm using GNU/Linux, if that makes a difference.
3
votes
3answers
843 views

linux launch script /etc/init with a specific user

I've created a script in /etc/init/mms-agent.conf : start on runlevel [2345] stop on runlevel [06] exec /usr/bin/env python /home/mms/mms-agent/agent.py >> /home/mms/agent.log 2>&1 ...
1
vote
2answers
3k views

Changing user in a script?

I am trying to change user in order to execute a specific command during startup. It fails silently and apparently the userchange isn't carried out as I can tell that the command isn't executed. What ...
2
votes
3answers
791 views

using here script I/O redirection with su command

here is my script. I want to login with another user and do ls -lih: #!/bin/bash su - testuser <<- _EOF_ 123456 #password _EOF_ ls -lih here is the output when i ran script: ...
9
votes
3answers
5k views

.bash_profile not sourced when running su

I have a user, say user1, which has modifications to its .bash_profile, one of them changing the PATH, e.g.: export PATH=/some/place:$PATH. This change works fine if I log on as user1 or do a su - ...
5
votes
3answers
2k views

Changing the UID of files in /proc

In a follow up to this question about changing the UID of a user, it is recommended to change the ownership of all files on the system (this answer) find / -uid 1000 -exec chown 5000 '{}' \+ where ...
2
votes
2answers
776 views

su - username -c “./script.sh” -> no such file or directory

We have: a user nico. a folder /home/nico/script_home with some bash scripts: main.sh subscripta.sh sqlscripta.sh We connect as root and cd /home/nico/script_home/ Finally we run ./main.sh We ...
0
votes
0answers
297 views

Why do you need sudo for “sudo su root”? [duplicate]

Possible Duplicate: When do su and sudo use different passwords? Why do you need to use sudo su root ? Why won't it work to just use su root?
4
votes
3answers
2k views

Find out if a session is running under `su`

I'm trying to check whether the current shell session is running within a su login session. What's the best way to test this condition?
7
votes
1answer
5k views

How to run a GUI program as a different user (Debian)?

Using a terminal, I can change the running user with su and sudo — but how can I do that by clicking on an icon/shortcut on the desktop/start menu? If I have to be root to execute I will be asked ...
8
votes
1answer
1k views

What is the difference between 'sudo' and 'su -c'

Is there any difference between using sudo and using su -c? There are situations where one should be used but not the other? I was previously using Ubuntu where sudo appears to be ubiquitous but now ...
2
votes
1answer
709 views

sulog with openSUSE 11.2 (x86_64)

I need to log as much as possible when users a doing su *... Best would be to log all commands especially for the case root does something as a user. We can assume root would not change this logging ...
11
votes
2answers
6k views

What is the difference between 'su -' and 'su root'? [duplicate]

Possible Duplicate: Why do we use su - and not just su? I understand that root doesn't have to be a superuser. But in the case that it is ... what is the difference between sudo su - and ...
4
votes
1answer
460 views

Why do I need to use newgrp or su (or logout and login again) to have new group memberships applied?

What is it that makes new group membership require a new login (or new login shell as started by su or newgrp) to be visible? Just running another bash (or whatever other shell) instance with --login ...
12
votes
1answer
912 views

What's the difference between sudo su - and sudo su --

When I am working on our RHEL machines, I use sudo su - to switch to being root. One day, a typo meant I typed sudo su -- instead - it seems to me that everything was the same as with a single hyphen, ...
5
votes
2answers
1k views

Alternative to su/sudo on barebone system

I'd like to run some unit tests in a barebone chroot jail on Solaris. There's no su or sudo, and a copy of su (with libpam.so.1) just returns exit code 1 without any output, with or without ...
2
votes
1answer
161 views

Is it possible to set su to use WE password dialog

I have sometimes problem when during entering password for su other window appears and steals the focus ("wait - did I just entered root password on public IRC chatroom?" - it did not happened but ...
1
vote
3answers
4k views

running multiple commands for su in bash

I would like to use su -c to run as root multiple commands altogether. I don't want to use an extra script for this. I tried the following su root -c "tcpdump -i wlan0 -s 1500 -w CCCCCC & " ...
2
votes
1answer
1k views

FreeBSD: Opening X applications after su to root?

Using FreeBSD 8.2. I'm accessing my machine over vnc using tightvnc. I log in as my normal user. This is okay. I can open X applications and they display fine. Then I su to root and they won't ...
13
votes
4answers
817 views

What is SSH - the protocol and what is ssh - the utility?

What is SSH - the protocol? What is ssh - the unix utility and how does it work? How is SSH protocol related to SFTP? What is sshd? Does the command su use ssh or sshd?
80
votes
7answers
11k views

Which is the safest way to get root privileges: sudo, su or login?

I would like to have the root account in safety even if my unprivileged user is compromised. On Ubuntu you can only use sudo for "security reasons" by default. However I am not sure it is any safer ...
3
votes
2answers
950 views

How to trace a process to original user?

Say, on a Solaris server, user1 logs in, switches to someother user, say sruser, using su - and then starts a process of id X. And then another user user2 logs in, switches to sruser the same way and ...
25
votes
6answers
14k views

What is the need for `fakeroot` command in linux

Why do we need fakeroot command at all? Can't we simply use the sudo or su commands? The man page says: fakeroot - run a command in an environment faking root privileges for file manipulation ...
3
votes
2answers
3k views

su vs su - (on Debian): why is PATH the same?

I know what should be the difference between su and su -, but in my system (debian testing) for example PATH is the same: [root]# su [root]# echo $PATH ...
6
votes
2answers
9k views

Is it possible to su without being prompted for a password?

I suspect su doesn't have any way to allow passing the password from the shell instead of being prompted for one, for security reasons (couldn't find anything in the MAN). Is this true?
74
votes
2answers
9k views

Why do we use su - and not just su?

I don't understand why su - is preferred over su to login as root.
7
votes
4answers
1k views

sudo permission denied but su grants permission

this is the first occurrence where su was required for me. I read an article about changing the value in /sys/devices/virtual/backlight/acpi_video0/brightness to alter my laptop's screen brightness. ...
5
votes
5answers
4k views

How do I suppress dd output?

I have a bash script that creates some file using dd. The problem is dd throws a great amount of output that is going to mess with the output of my script. Searching around I've found a solution: dd ...
4
votes
3answers
934 views

`$XAUTHORITY` appears from 'nowhere' on su+tmux

When I switched from su+bash to su+tmux+zsh I noticed that I get $XAUTHORITY variable defined as /root/.xauthXXXXXX where XXXXXX are 6 random alphanumeric characters. With previous configuration X ...
9
votes
2answers
3k views

When do su and sudo use different passwords?

I am able to run anything using sudo; my password is accepted. But whenever I try to do su from a shell, it fails with: su: incorrect password What can the problem be?
73
votes
6answers
21k 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 ...
3
votes
2answers
11k views

su options - running command as another user

I was wondering how to run a command as another user from a script. I have the script's owner set as root. I also have the following command being run within the script to run the command as the ...