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

learn more… | top users | synonyms

2
votes
1answer
274 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
3k 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
9k 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
1k 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
1k 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
491 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
3k 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
1answer
936 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
415 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
1k 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
102 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
127 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
210 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
124 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
196 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 ...
0
votes
3answers
771 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
126 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 ...
4
votes
2answers
18k 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
261 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
205 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
982 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
617 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
9k 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
75 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
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 ...
4
votes
2answers
398 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 ...
8
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
2k 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
401 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
212 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
1k 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
2k 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
4k 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.
6
votes
4answers
3k views

Why can't we execute a list of commands as different user without sudo?

This question has been asked in a different way in other forums. But there has not been a decent explanation why you can't do the below in bash. #!/bin/bash command1 SWITCH_USER_TO rag command2 ...
0
votes
2answers
7k 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 ...
1
vote
3answers
123 views

Is there any way to disable shutdowning remote machine?

I sometimes mistakenly shutdown the remote machine by using sudo init 0, so I wrote something like in one of my rc files: alias sudo='sudo ' if [ $SSH_CLIENT ]; then alias init 'echo Never use init ...
1
vote
3answers
110 views

Confused on user and su in linux

How could I run a script as a specific user (non-root)? As this? sudo su - john /usr/share/script.pl for user john?
1
vote
2answers
228 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
4k 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 ...
1
vote
1answer
138 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 ...
3
votes
3answers
6k 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 ...
15
votes
4answers
17k 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 ...
0
votes
3answers
107 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
7k 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
221 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.
2
votes
0answers
124 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 ...
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 ...
1
vote
1answer
172 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 ...
2
votes
3answers
6k 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 & " ...