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

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13
votes
3answers
9k 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 - ...
2
votes
1answer
63 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
1k views

Running GUI application as another (non-root) user

Let's say I have 2 user accounts user1 and user2. When I login as user1, and then switch to user2 using su, I can execute command-line programs, but GUI programs fail. Example: user1@laptop:~$ su - ...
0
votes
2answers
404 views

Error when running X11 application as root

I get this wierd error when I run applications as root. **(gedit:630): WARNING **: could not open X display No protocol specified Unable to init server (gedit:630): Gtk-WARNING **: Cannot open ...
2
votes
1answer
287 views

su not asking for password

My su does not ask for password. When I run su it simply logs me in to root. I tried su - root then it asks for password. Now, because of this kdesu runs applications with root rights without ...
1
vote
2answers
124 views

Problem executing command as differetn user with sudo -u

I have the following problem When I'm trying to execute ls as user abc with the following command I get an error: xyz@host:~/temp$ sudo -u abc ls [sudo] password for xyz: Sorry, user xyz is not ...
2
votes
2answers
96 views

Making su ask for password multiple times

Is there some way to make su ask for the password again in case of a wrong password (just as sudo does)? Initially I thought of this: while ! su -c foo; do read -n 1 -p "Retry(y/n)?" ch if [[ ...
1
vote
1answer
31 views

How do I switch user without any references to the old one?

A while back, when playing with unprivileged LXC, I discovered that the command to create a container failed if I used su to switch to the user, but it worked if I used ssh user@localhost to login. ...
3
votes
1answer
509 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 ...
4
votes
1answer
2k views

Command : must be run from a terminal

I have a shared hosting account, I logged using ssh. when I type for example su I had this output : su: must be run from a terminal Is this error relative to the fact that I don't have sufficient ...
2
votes
3answers
178 views

Can sudo replace su?

There is much duplication of functionality on Linux-based systems, for example these do the same thing: sudo --login --user <user> sudo su - <user> The sudo-only approach looks more ...
7
votes
3answers
2k views

Difference between sudo -i and sudo su [duplicate]

I was wondering what the difference is between sudo -i and sudo su?
0
votes
1answer
218 views

How do you keep the password hidden when invoked during the su command?

This is the first time it has happened to me where I am using the su command and it actually displays the password on the terminal and doesn't stay hidden. Here is my code snippet: sshpass -p ...
87
votes
6answers
27k 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 ...
2
votes
1answer
218 views

How to create an executable bash script for these commands?

I wish to create an executable bash script that will run the following commands as root, that is, using sudo su iptables-save | awk '/^[*]/ { print $1 } /^:[A-Z]+ [^-]/ { print ...
1
vote
3answers
2k views

Wrong Permission to /etc folder [duplicate]

I have given the wrong permission to the /etc folder chmod -R 777 /etc When I want to login as root it gives me an error and the following output. How can I correct the permissions? ...
1
vote
2answers
6k views

How can i run a part of a script as a different user?

#!/bin/ksh (some code) Log=~/my.log chown USER1 filename su - USER1 -c " date | tee -a ${Log} 2>&1; cd /blah/blah if [ SOMECONDITION ] then sh ./somescript.ksh > logfile fi exit" | tee -a ...
1
vote
3answers
423 views

How to return from root log-in to my user log-in?

I'm using SuSE Linux Enterprise and I know that there is a command su root for changing to root log-in. But what about the other way around? If I prefer to return to my user account, how to do it? ...
4
votes
3answers
994 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 ...
1
vote
1answer
227 views

su to another user using ssh keys?

Assuming that user_A and user_B set up and exchange public ssh keys with each other, is it possible for user_A to su into user_B on the same machine?
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 ...
0
votes
0answers
27 views

Help Parsing `su` Command … What Does the Hyphen Do? [duplicate]

In the command su - username, what is the function of the hyphen? It seems to work all the same without the hyphen.
2
votes
1answer
568 views

root login silently fails

After some months of not touching it I wanted to login to one of our virtual servers to update OpenSSL, because of the heartbleed thing. The server is running Debian 7, sudo is not installed. I ...
8
votes
2answers
284 views

How do I elevate privileges in the middle of pipeline?

My guess was as follows: echo "Generating some text" | su - -c cat >/output/file But su says: su: must be run from a terminal What would you do?
3
votes
2answers
686 views

Passing arguments to su-provided shell

man su says: You can use the -- argument to separate su options from the arguments supplied to the shell. man bash says: -- A -- signals the end of options and disables further option ...
1
vote
1answer
93 views

Why would we su without -? [duplicate]

When we do su John I switch as user John. When we do su - John I switch as user John having user John's environment. As far as I can see the first option is useless. What is the use of switching to ...
2
votes
2answers
112 views

How do I emulate su's behavior with sudo?

I'm trying to make sudo ask for target password, except when run by root. Here's what I do: Defaults:!root targetpw This way it asks for my password, and if I make it like this: Defaults:yuri ...
1
vote
2answers
99 views

How to log out of su and another user

So when I am logged in as a standard user in an ssh session and then su to root, how can I log out of both accounts with a single command? Rather than: root@host:/exit user@host:/exit something ...
1
vote
1answer
85 views

Changing the PATH variable for a process running as a user on Linux

I have a server application which I start using an init.d script and run as a user: su $USER -c "${PLAY} start ${APPLICATION_PATH} --%prod-test >/dev/null" The application needs ffmpeg, which is ...
2
votes
1answer
139 views

Impossible to execute a command by using su for another (system) user

I've created my user like this: sudo adduser --disabled-password --system --home /var/lib/deluge --gecos "Deluge server" --group deluge The content of /etc/passwd: deluge:x:110:114:Deluge ...
2
votes
2answers
394 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 ...
0
votes
3answers
477 views

Can sudo to user but 'run command as' is denied?

I was wondering how to run a command as another user from a script without password. sudo -l return: (root) NOPASSWD: /bin/su - someuser There is no problem to sudo as someuser. Command sudo su - ...
1
vote
1answer
97 views

super user group or user?

I am using the following command in Oracle Exadata: sudo su - odiadmin As sudo prompts for my own password, I am wondering if I upgrade myself to super user or do I switch to superuser ...
2
votes
2answers
10k views

Cannot connect to X server :0.0 as superuser

When I am online, I get following error and the tool does not start: [root@dhcppc9 lin64]# ./ise No protocol specified _pn: cannot connect to X server :0.0 But everything is OK when I am not a ...
0
votes
1answer
179 views

Why can't I su when if I am in the wheel group in OpenBSD?

Using a OpenBSD 5.4 (GENERIC) #37: Tue Jul 30 15:24:05 MDT 2013 I created a new user named "bela" and added it to the wheel group: # adduser Use option ``-silent'' if you don't want to see all ...
4
votes
1answer
170 views

Is there any point in using `sudo` when you are the sole user of your machine?

I'd like to know if there is any reason why I should use sudo instead of su, taking into account that I am the owner and sole user of my machine (and hence have root access whenever I want). Also, in ...
1
vote
0answers
769 views

Automate `pbrun su` via plink

I am trying to automate an sFTP process for our project. When I login with PuTTY and manually type the command pbrun su - user1, root access is given to user1 and I am able to do the sFTP process. I ...
0
votes
1answer
423 views

How to get pid of su --session-command file thats ran on there [closed]

This line ran in a script su --session-command="$javaCommandLine & >>$serviceLogFile 2>&1 & echo \$! >$pidFile" $serviceUser || return 1 pid="$(<$pidFile)" echo $pid The ...
3
votes
2answers
6k 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 ...
1
vote
0answers
72 views

can't access account with empty password

I used the passwd command to remove the password for my account. Now, when I try to use su to log in to my account, it won't let me enter an empty password. So now, I can't access my account. Any ...
2
votes
2answers
3k 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 ...
4
votes
2answers
318 views

How do I execute a command on login for a system user with no home folder and no personal .bashrc file?

I set these users' home folders through the /etc/passwd file, but when they log in I would like them to activate a python virtualenv. If they had a personal .bashrc file, I'd just include the activate ...
7
votes
4answers
2k 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. ...
0
votes
3answers
1k views

How to gain root privileges for specific user if we have root password? [closed]

Can someone suggest how can I change process privileges in Linux to root ? Assume, I have a normal process running under some user-consider me. Now my script should create some users using 'useradd' ...
1
vote
2answers
288 views

Can't run su after changing permissions to su file

I am running Linux Slackware 14.0. I wanted to allow to do su only to the members of wheel group, so I modified the permissions of /bin/su and /usr/bin/sudo files to this: bash-4.2# ls -la /bin/su ...
5
votes
1answer
174 views

How to allow to run su instantly after I added the user to the appropriate group

I have the su executable with the following permissions: bash-4.2# ls -la /bin/su -rws--s--- 1 root wheel 59930 Sep 14 2012 ./su When I am logged in as a user, not in the wheel group and try to ...
0
votes
3answers
727 views

Create a file as a different user and group

I have a bash script with downloads some files, and then needs to set the owner to apache, and the group to a particular user group (that apache is not a member of). Is there a way to create those ...
5
votes
2answers
1k views

how to ssh -Y and then su - <another user> and still forward X applications to your local machine

it is easy enough to 'fetch' (ie draw locally) a remotely running linux application: If I ssh -Y to the remote machine and run an application, that application will surely enough pop up in my local ...
1
vote
1answer
2k views

How does this su -c “…” command seem to pass two commands instead of one?

I am trying to understand the script below and I am confused about the su line. I understand the postgres command line arguments. when I do man su the manual says -c, --command=COMMAND ...
0
votes
1answer
58 views

I want to create a script so that I don't have to type su and password every time [closed]

I want to create a script so that I don't have to type su and the password for logging into root every time.