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

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2
votes
2answers
429 views

How to source correct startup scripts on interactive, non-login shell

I'm trying to set up a sane/usable environment in a barebones OpenSolaris-derivative (OmniOS, a distribution of Illumos/OpenIndiana). I have all the plumbing code I need in .profile, .inputrc, and ...
1
vote
2answers
189 views

Staggering the authentication delay on failed `su` or `sudo` [duplicate]

I'm about to start my new job as a sysadmin and I've been thinking about implementing a cooldown feature on su or sudo. The cooldown prevents the user from using these commands for a few seconds after ...
3
votes
2answers
3k views

Setting umask for su root

In my user account I set the umask to be 022 with my .bashrc, but I want root to use a umask of 077 no matter how I become root (e.g., logging in directly as root on a tty or using sudo or su). If I ...
2
votes
2answers
4k views

How can I mimic `sudo su - user` in a script?

I need to deploy my app to server called lovelyplace by a Fabric script. Unfortunately, the server's setup is horrible, but I can do nothing about it - I have to live with it. There is one non-root ...
1
vote
1answer
123 views

ssh key authentication not working from network/if-up.d/ scripts

I have two nearly identical scripts in network/if-up that need to access SSH keys. Permissions on SSH private keys are 600, so how can my scripts access these keys? I would prefer to keep the SSH ...
0
votes
3answers
105 views

Is there a way to switch to “su -” after switching users through “su”?

Maybe the title wasn't worded quite clear. But basically what I want to be able to do is to switch to having used "su -" instead of the traditional hyphenless "su" after already using "su" to switch ...
1
vote
1answer
5k views

can't ssh into remote host with root, password incorrect

I have a remote host, previously I can ssh into it with root and password ssh root@remote_host or I ssh into it first using a regular user account ssh esolve@remote_host and then su root and ...
1
vote
1answer
157 views

su command with -p or -m flags

What is the difference between the following su commands? su -m su -p I know that both flags are used to preserve the current environment but I don’t know the differences if there are any.
3
votes
1answer
4k views

Stop su from asking for a password

I am trying to run the following command as deploy from Java (the JVM is running as the user tomcat): sudo -u deploy /path/to/my/bash/script.sh PARAM1 PARAM2 My sudoers file has the following in ...
2
votes
0answers
120 views

Understanding getlogin spoofing

My question is in three (or so) related parts: 1) My understanding is that getlogin() will effectively return the auid associated with the process and so isn't actually changable by the user. Is that ...
1
vote
1answer
151 views

New Terminal not works when we use su root

When I use su root and then use gnome-terminal I get warning ** (gnome-terminal:2677): WARNING **: Failed to connect to the session manager: None of the authentication protocols specified ...
0
votes
1answer
869 views

Difference between sudo su - user and sudo -iu user [duplicate]

I was wondering if there were any difference (in environment ?) between doing sudo su - user and sudo -iu user From what I know: By using sudo su - user I open a new shell as user, and the ...
4
votes
2answers
494 views

Two GUI applications as different users on the same screen

I am logged as user A. I want to run a GUI application as user B. User, not root. User B is local too, not remote, I only need different environment variables. I don't want to run the second X, I want ...
-1
votes
1answer
1k views

Where does sudo get the currently logged in username from?

When I tried to "sudo su" instead of "sudo su -" after having been logged in as root and su-ing to another user, it tries to sudo me as the new user, but via root... When I type env, it shows still ...
2
votes
3answers
2k views

Using sudo in openSUSE without actually changing to root user (i.e., like in Ubuntu)

I recently started trying openSUSE 12.3 after having used Ubuntu for a few years. I'm still getting used to openSUSE's treatment of su (and sudo) vs. Ubuntu's use of sudo. I've been reading the ...
13
votes
4answers
14k views

Why doesn't “sudo su” in a shell script run the rest of the script as root?

A sample script can be as below: #!/bin/bash sudo su ls /root When using ./test.sh as the normal user, instead run ls as super user and exit, it switches to root; and when I logout, it executes ls ...
2
votes
2answers
234 views

How to su to www on OpenBSD?

I have a PHP script that I wish to run under the www account. The account has nologin as shell and is used by Apache. When I run "su -l www -s /bin/ksh" as root, I get the following message: This ...
0
votes
3answers
1k views

What does sudo su work but su does not? [duplicate]

I have tried this on Fedora and on Ubuntu. kshitiz@kshitiz:~$su su: Authentication failure kshitiz@kshitiz:~$sudo su root@kshitiz:/home/kshitiz# I am entering the same password in both the cases. ...
2
votes
1answer
435 views

Setting the root password vs. sudo -i

Should one always set a root password, or is sudo -i acceptable? Two problems is in reading other posts (maybe junk I realize): sudo -i eliminates the need for a password. Isn't that a problem for ...
4
votes
4answers
4k views

Should I use `sudo` or `su` in a startup script?

I have a personal program, that has a server/client design. The server daemon part of it, should be run as its own limited user, and the program was not designed to drop its root privileges (if ...
2
votes
1answer
3k views

Can't use su or sudo on Arch Linux

Sudo returns this error: sudo: effective uid is not 0, is sudo installed setuid root? And su - returns this: su: Authentication failure The user I'm using is a member of the following groups: ...
8
votes
1answer
1k views

How to stop users from Switching to Root user

I have disabled the root user login from Sshd.conf file so now no one can login using root user even if they know the password SOMEHOW. Now I have 3 users in server ROOT,EMERG and ORACLE. I want to ...
2
votes
3answers
4k views

su: Permission denied despite correct password

In my new Gentoo installation, su doesn't work as my non-root user: After entering the correct password I get the message "su: Permission denied". What could be causing this? I have already tried ...
0
votes
1answer
298 views

SSH minimal rights user - su only [duplicate]

Possible Duplicate: Creating a UNIX account which only executes one command I am trying to setup a user account that only has as minimal rights as possible. The user should be able to log ...
9
votes
1answer
953 views

Why does “su -c <command> &” seemingly allow a command to run in the background without hanging up

I was helping a colleague who was having problems with a background process intermittently dying. I found out that they were starting the background process by logging in to the server and executing: ...
6
votes
2answers
286 views

Why doesn't su change the user ID of the shell from which it was run?

Instead, it starts a new shell process with the new user ID. The original shell is blocked until the new shell completes and su exits. Why does it work like this?
3
votes
1answer
514 views

Why can I only use apt-get when I use “su”?

Not sure what info you need here, if any. Just let me know. I have a proxy that bypasses the corporate net set in my profile file for both su and normal user. When I do a sudo or regular apt-get ...
0
votes
1answer
3k views

How to use sudo in Fedora?

I use to be a fans of Ubuntu, when I want to execute a command as root user, I do this sudo blah_blah_blah. But in Fedora 16, it doesn't seem recognize this command. Any clue on this?
0
votes
1answer
706 views

script to switch users keep running? [duplicate]

Possible Duplicate: Switching to superuser while shell script is running I need to switch users in a script and keep executing commands. I thought -c would help but i don't know how to use ...
1
vote
3answers
2k views

Ask root for password when using su command

I'm trying to edit /etc/sudoers via visudo, but I don't know how to change the root rights. I want root to be prompted for the user1's password, when he tries to use su user1.
1
vote
3answers
2k views

Shell script to become root

How can we write a shell script to become root? That is I donot want to input the password at prompt it should be within the script itself. I was trying to make but failed to do so.Is it possible, if ...
0
votes
2answers
898 views

How to suppress su authentication failure warning?

I created an account "diag" and set it as expired (usermod --expiredate 1). Then I have a script which I want to run to log into it, so in the script I use the following command: su -s /bin/bash - ...
2
votes
1answer
334 views

su and redirection

The following line shows the principle of a construct which I can use under Red hat 5.5: $ echo "foo" | ssh myhost "echo \"cat <&1\" | su --login" foo Actually it was never clear to me why ...
0
votes
2answers
6k views

Avoid asking password if `su -m user command` is used under `user`?

If I run the script containing su -m user service userservice start under root user, I do not need to enter the password. But when I run it under user user, it asks passwords all the time. That really ...
0
votes
1answer
2k views

su authentication failure after setting new password

I compiled a new kernel(3.2) and I have it running on an ARM board. I wanted to enable some params on the /proc directories. Therefore I have to be logged in as root. Hence I did the following on my ...
4
votes
2answers
4k views

Change user and load entire environment in shell script

I'm having some trouble with an upstart script of ours that changes user and starts up a few ruby daemon processes. In the past i would simply bash -c "do the business" -l someuser making sure to use ...
3
votes
2answers
389 views

Am I using bash after this ordeal?

On Mountain Lion, host Coguaro, I login as user coconutpowder using bash: Coguaro:~ coconutpowder$ echo $0 -bash I need to run a command with elevated privileges so I try to su switch to root but ...
2
votes
1answer
901 views

su-to-root fails when root user locked?

How might I use script /usr/bin/su-to-root after I have intentionally locked the root account? Running Debian GNU/Linux 6.0.5 "squeeze" and noticed menu item "System > Administration > Synaptic ...
4
votes
3answers
2k views

Automate login with sudo and su

I know the security risks, but I am performing this experiment/exercise on an old, seldom used *nix machine I have laying around the house. So doing this exercise will not bring any security risk to ...
2
votes
4answers
3k views

Allow paswordless user to change to another passwordless user

I have two users dev and tomcat neither of them have a password. How can I allow dev 1 do su - tomcat without having him having to enter any credentials? 1 connects with ssh keyfile
2
votes
3answers
2k views

Switching to superuser while shell script is running

I have a shell script that contains the following lines: CURRENT_USER=${USER} echo $CURRENT_USER su echo switch to `who am i` Once the 2nd line is executed, the shell prompts me to enter the root ...
1
vote
1answer
594 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
172 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
4k 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
545 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 ...
19
votes
2answers
11k 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
2k 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
14k 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
1k 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
5k 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 ...