sudo - Execute a command with superuser privileges.

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56
votes
5answers
5k views

Redirecting stdout to a file you don't have write permission on

When you attempt to modify a file without having write permissions on it, you get an error: > touch /tmp/foo && sudo chown root /tmp/foo > echo test > /tmp/foo zsh: permission ...
47
votes
8answers
72k views

How to run a specific program as root without a password prompt?

I need to run something as sudo without a password, so I used visudo and added this to my sudoers file: MYUSERNAME ALL = NOPASSWD: /path/to/my/program Then I tried it out: $ sudo ...
47
votes
4answers
53k views

How do I run a command as the system administrator (root)

I need to run a command with administrative privileges. Someone said I should run a command as root. How do I do this?
93
votes
8answers
14k 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 ...
26
votes
2answers
13k 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 ...
57
votes
3answers
4k views

How do the internals of sudo work?

How does sudo work internally? How is it possible that it can become root without having the root password, unlike su? What syscalls, etc. are involved in the process? Is it not a gaping security hole ...
22
votes
2answers
5k views

How can I `alias sudo !!`?

I'm trying to set an alias for sudo !! in Bash. I tried alias sbb='sudo !!', but it interprets that as a literal !! and prints sudo: !!: command not found If I use double quotes, it substitutes ...
12
votes
1answer
30k views

How to add a user to sudoers file?

I have an account named as Chankey (local user). I had to use some commands like viewing the shadow file etc. I tried it using sudo command sudo vim /etc/shadow It said: Chankey is not in ...
10
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?
8
votes
5answers
1k views

Set sudo password differently from login one

As a privileged user I am trying to set the sudo password to another then the one used at login. I have done some research but have not found an answer. Does sudo support that kind of configuration? ...
98
votes
6answers
32k 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 ...
12
votes
1answer
15k views

Why does cron silently fail to run sudo stuff in my script?

I have a script run from a non-privileged users' crontab that invokes some commands using sudo. Except it doesn't. The script runs fine but the sudo'ed commands silently fail. The script runs ...
13
votes
3answers
9k views

Execute a line of commands with one sudo

For example if I want to create a file and enter text in one line I can redirect the output into a file with the use of the > operator: echo "something" > /path/foobar but if I don't have ...
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. ...
8
votes
4answers
4k views

Copying protected files between servers in one line?

I'd like to copy squid.conf from one server to another. The servers don't talk to each other. I'd like to go through my workstation. Both servers have the file, so it will be overwritten on the ...
8
votes
1answer
4k views

Why can't sudo redirect stdout to /etc/file, but sudo 'nano' or 'cp' can? [duplicate]

Why does redirection, using sudo give me an error for the following commands? $ sudo printf "foo" >/etc/file bash: /etc/file: Permission denied $ sudo printf "foo" ~/file; cat ~file ...
62
votes
20answers
10k views

Root access that can't change root password?

We are having a little problem on a server. We want that some users should be able to do e.g. sudo and become root, but with the restriction that the user can't change root password. That is, a ...
47
votes
5answers
4k views

Becoming root from inside Vim

Sometimes I start editing configuration files in /etc using Vim, but forget to use sudo to start Vim. The inevitable result then is that after finishing my edits I encounter the dreaded notice that I ...
27
votes
3answers
60k views

How to make Fedora user a sudoer?

I want to give a Fedora user sudo privileges. How do I do that?
20
votes
3answers
8k views

How is sudo intended to be used?

I've tried configuring sudo before, but I haven't had too much luck with it. How is it different from su -l -c "x"? It seems that via the configuration file, one can make it so a user can only have ...
3
votes
1answer
3k views

pass 1 environment variable using sudo

Is this a correct way for passing an environment variable in sudo ? sudo -u www-data -b env FOOBAR="foobar" /home/user/folder/daemon
8
votes
2answers
619 views

How do I edit a file as root?

Are there any special considerations to editing a file as root? What is the safest way to do this?
16
votes
1answer
2k 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, ...
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 ...
5
votes
1answer
124 views

Is it safe for my ssh user to be given passwordless sudo for `apt-get update` and `apt-get upgrade`?

I have an SSH standard user account on my personal server, and it has sudo access (via its password). I ssh in using a public key, so I don't have to type in the account password to log in. Is it ...
4
votes
3answers
1k views

What mechanism prevents any user from accessing any other user's files via root?

On a multi-user system, what protects against any user accessing any other users files via root? As context, the question is based on my understanding as follows: There are two commands related to ...
73
votes
4answers
75k views

Why do I need a tty to run sudo if I can sudo without a password?

I have configured sudo to run without a password, but when I try to ssh 'sudo Foo", I still get sudo: sorry, you must have a tty to run sudo. Why does this happen and how can I work around it?
40
votes
5answers
10k views

Why doesn't the sudo command need the root password?

I've been using Linux for a while now and whenever I typed sudo I thought I was switching over to the root user for a command. Apparently this is not true because all I need is my user account's ...
21
votes
2answers
31k views

How to disable requiretty for a single command in sudoers?

I want to disable requiretty so that I can sudo within scripts, but I'd rather only disable it for a single command rather than everything. Is that possible within the sudoers config?
18
votes
2answers
11k views

What is the proper sudoers syntax to add a user?

According to the comments in /etc/sudoers (Fedora 13): ## Syntax: ## ## user MACHINE=COMMANDS ## ## The COMMANDS section may have other options added to it. My two related questions: What ...
16
votes
3answers
12k views

How to make `sudo` preserve $PATH?

I need to run a program installed on /opt/godi/sbin (a custom directory). If I add that directory to my PATH, by adding the following line to my .bashrc file export ...
7
votes
4answers
18k views

How to restrict to run commands in specific directory through SUDOERS?

I can configure sudo (via the sudoers file) to allow a user to run the chown and chmod commands on any file or directory in the system. However, I only want to grant a user permission to run these ...
10
votes
5answers
19k views

Can a linux user change their password without knowing the current password?

I'm setting up a few ubuntu boxes, and using opscode's chef as a configuration tool. It would be fairly easy to install public keys for each user on each of these servers, and disable password ...
8
votes
5answers
15k views

How to get back sudo on Ubuntu?

I have done this: sudo chown -R myname /usr/ and now I can't use the sudo command because of this error: sudo: must be setuid root And as I read this means that the owner of this file ...
6
votes
2answers
3k views

System Crontab or Root Crontab

System crontab: /etc/crontab Root crontab: sudo crontab -u root -e Which way is preferred? As they all run tasks within administration privilege.
6
votes
1answer
244 views

Keeping sudo authentication with gnome-terminal

Can sudo sessions be shared across tabs of gnome-terminal, so that once I use sudo in one tab, I won't have to re-enter my password every time I open another tab and use sudo?
6
votes
1answer
9k views

Allowing a user to use sudo without a password

On a sandbox VM environment, I have a setup of Ubuntu Linux which is firewalled and cannot be accessed from outside the local system. Therefore, on that VM, I'd like to give the administrative user ...
5
votes
5answers
30k views

How to start a program in the background

The program Boblight does not run in background. There is no noticeable difference between executing sudo boblightd and sudo boblightd& How can I solve this problem that the console will ...
14
votes
4answers
483 views

What specific vulnerabilities am I creating by disabling the sudo password?

Here are some instructions on how to disable your sudo password. These carry the following warning If you disable the sudo password for your account, you will seriously compromise the security of ...
7
votes
1answer
102 views

How does the Linux desktop perform system actions?

The Linux desktop can perform several actions which is otherwise not available to the user when logged in from a terminal. Actions such as system shutdown, and changing system time are accessible only ...
3
votes
1answer
1k views

Copy a local file to a remote server, non-root privileges over sudo?

I'd like to do something like: scp local_file remote_server:/some_directory But in order to gain privileges to /some_directory, we need to call sudo. I know that a similar question had already been ...
2
votes
3answers
791 views

Why does sudo ignore aliases?

I am running Ubuntu 10.04 and I use upstart for daemon management. My enterprise application is run as a daemon and must be run as root because of various privileges. E.g.: sudo start ...
1
vote
1answer
144 views

Getting sudo to work for an alias

I installed Sublime Text 3 in Fedora 20 which has got GNOME, as I couldn't get it being called from terminal I created a .bash_aliases file which a line like this: alias sublime='sublime_text' And ...
1
vote
4answers
18k 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.
13
votes
3answers
5k views

How do you process an entire command as sudo that involves redirecting or piping?

I am trying to follow what I assume is best practises of using sudo instead of root account. I am running a simple concat file operation such as: sudo echo 'clock_hctosys="YES"' >> ...
8
votes
2answers
11k views

using sudo on GUI applications

When I was using kubuntu, I could always open X applications with sudo, sudo kate for example. Now that I've switched to arch that doesn't work. I know I've always been told to use kdesu, but what ...
3
votes
4answers
17k views

How to login as root from Bash and do stuff

This is my simple bash: cat test.sh #!/bin/bash echo "hello" su - root -c /path/to/script.sh <<EOF password EOF whoami echo "good bye" But I get this error: ...
3
votes
1answer
308 views

How to use SCSUDO to run scripts with positional parameters?

I am trying to use scsudo to run a number of defined commands to stop and start processes on a UNIX host. The issue I am experiencing is that scsudo does not seem to like the use of positional ...
2
votes
2answers
122 views

Prompt for sudo password rather than give access error

Can I configure Fedora 22 so anything needing root privileges asks for a password, rather than giving an error, and needing me to re-run with sudo? I wouldn't even mind having to type my password ...
1
vote
3answers
5k views

How can I scp a file that my user can't read but I can sudo?

Can I use scp to copy a file from a remote server which my login user can't read, but where I have permission to sudo to root (without password even)? How?