sudo - Execute a command with superuser privileges.
69
votes
7answers
7k 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 ...
48
votes
5answers
9k 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 ...
35
votes
2answers
2k views
Why do we need to use visudo instead of directly modifying the sudoers file?
I understand that if you want to modify who can use sudo and what they can do with it that you should use visudo. I know I'm not suppose to directly modify the sudoers file myself. What is it that ...
28
votes
4answers
1k 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 ...
24
votes
5answers
6k 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?
23
votes
4answers
2k 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 ...
19
votes
1answer
1k views
How to get root inside of vi? [duplicate]
Possible Duplicate:
Becoming root from inside Vim
It could happen to anyone. The admin types:
vi /etc/resolv.conf
as a regulare user. He edits the /etc/resolv.conf file, but when he ...
17
votes
3answers
909 views
Where can I find documentation about the “sudo !!” command
I just learned that Linux has a sudo !! command which literally applies sudo to the last entered command. I had never heard about it.
Is that a common control? Where can I find documentation about ...
16
votes
5answers
7k 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
...
15
votes
4answers
28k views
15
votes
2answers
1k views
How does sudo remember you already entered root's password?
When using sudo on Linux, it asks for root password, but only the first time you run it. If you run another sudo command, it remember you already entered the password previously and doesn't ask for ...
14
votes
3answers
4k views
How does sudo work?
I've tried messing around with 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 ...
12
votes
4answers
600 views
How universal is sudo?
I was writing some instructions on how to install something (TeX-related - if you don't ask, I won't ruin your day by supplying more details) and used sudo to install system-wide. Someone commented ...
12
votes
2answers
3k views
Is it possible to save as sudo from nano after you've forgotten to run as sudo?
A lot of the time I edit a file with nano, try to save and get a permission error because I forgot to run it as sudo. Is there some quick way I can become sudo without having to re-open and re-edit ...
11
votes
3answers
280 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 ...
11
votes
2answers
1k views
zsh wants to correct vim to .vim
I'm using zsh on Gentoo x64, and when I type sudo vim /path/to/file from my home folder, zsh asks:
zsh: correct 'vim' to '.vim' [nyae]?
I want to run vim not my .vim folder. How do I fix this?
...
10
votes
2answers
823 views
How to safely pass variables to root-enabled scripts?
This question is totally general and not only applicable to my situation, but... I have a small busybox appliance where I want a non-root user to be able to execute a particular script with root ...
10
votes
3answers
3k views
sudo cannot open /etc/sudoers
sudo does not work.
I have installed Arch Linux onto a USB key formatted with BTRFS.
The output of sudo is:
$ sudo
sudo: unable to stat /etc/sudoers: Permission denied
sudo: no valid sudoers sources ...
9
votes
4answers
707 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 ...
9
votes
2answers
2k 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 ...
8
votes
2answers
2k 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
3answers
2k views
Prompt for sudo password and programmatically elevate privilege in bash script?
I'm currently working on a bash script that installs and sets up various programs on a stock Linux system (currently, Ubuntu). Because it installs programs and copies a number of files to various ...
8
votes
6answers
3k views
Is there a way to stop having to write 'sudo' for every little thing in Linux?
I'm a newbie when it comes to Linux. I do most of my development in a Windows environment. That said, I'm going to be doing a fair amount of PHP work shortly, and I'm interested in learning RoR, so ...
8
votes
2answers
5k 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 ...
7
votes
4answers
12k 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 ...
7
votes
2answers
1k 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 ...
7
votes
2answers
5k views
Does mount always require root privileges?
I was under the impression that any sort of call to mount requires root privileges.
But recently I was told "You should instead create appropriate entries in /etc/fstab so that the filesystems can be ...
7
votes
2answers
1k views
Forcing sudo to prompt for a password
If I do the following:
sudo su -
//enter password
exit
exit
//login again straight away
sudo su -
The second invocation of sudo does not request a password because even though I have logged out ...
7
votes
2answers
981 views
Once sudo su'd to root, is there a command to see my username?
I have sudo rights on a redhat box; once I've "sudo su -" to become root in a shell, are there any commands I can run to see what username I su'd FROM?
7
votes
1answer
549 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, ...
7
votes
3answers
6k views
`/etc/sudoers` — specify `env_keep` for one command only?
Is there any way to specify that sudo should preserve certain environment variables for specified commands only? For some purposes I'd like my $HOME env. variable preserved when I run certain ...
7
votes
3answers
1k views
Why does my sudo ask for password only once but evaluate thrice?
$ sudo some_command
Password:
Sorry, try again.
Sorry, try again.
Sorry, try again.
sudo: 3 incorrect password attempts
$
This is what my shell prints when I enter a wrong password to a sudoed ...
6
votes
5answers
4k views
Can I change root password by sudo, without su?
I can sudo, but I don't have the root password so I can't su root. Using sudo, can I change the root password?
6
votes
3answers
993 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.
...
6
votes
7answers
761 views
Negatives/downsides of Ubuntu's no-root sudo setup
By default, Ubuntu does not create a root account that the user can login to. Instead users use sudo when they need to perform actions that require administrative access.
Obviously, the people at ...
6
votes
2answers
5k views
How to set visudo to use a different editor than the default on Fedora?
Fedora 14 uses vi by default when one runs visudo. Is there a way to change this to something else?
6
votes
2answers
2k views
How do I get sudo -u $user to use the users env?
It seems when sudoing down that using sudo -u $user that the environment of root is still being used. How can I make sudo use the users environment? as a special note not all users that I will be ...
6
votes
3answers
3k views
Why do some packages use 'make install' while other use 'sudo make install'
I recently installed LAME encoder on my server to convert wav to mp3 and that worked with './configure, make, make install;
I then tried to install OGG encoder and that requires './configure, make, ...
6
votes
2answers
2k views
Why is sudo telling me my password is wrong?
I recently installed OpenBSD 4.9 in my computer, so I could learn a little bit about Unix-like operating systems. I added a new user to the system called bruno. Ok. When I use the 'sudo' command, it ...
6
votes
1answer
446 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 ...
6
votes
4answers
3k views
What environment do I get with sudo?
When I run sudo, what exactly happens to my environment?
When I run sudo command, it doesn't seem to see my or root's environment. For example, my path for both includes /usr/local/bin, but if I try ...
6
votes
1answer
584 views
sudo missing on Palm WebOS - can I add it?
I've rooted my Palm Pre (WebOS 1.4.5) and installed a SSH server on it. Now I'd like to SSH into it with an unprivileged user and use sudo for elevated commands.
However: There is no sudo on the ...
5
votes
2answers
2k views
tail program output to file in Linux
I know we can use below format to redirect the screen output to a file:
$ your_program > /tmp/output.txt
However when I used below command, it says "-bash: /home/user/errors.txt: Permission ...
5
votes
2answers
2k views
Write to a file without redirection?
I am writing a regular compiled application that needs to create a special file and write a magic cookie into it. I can’t write the file directly from the application, the system security model ...
5
votes
3answers
2k 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 ...
5
votes
3answers
181 views
Are sudo and gksudo safe?
I noticed after running a sudo command in terminal or running a administrative application that uses gksudo, it won't ask again for the password for a time (something like 5 minutes).
Now let's ...
5
votes
3answers
4k views
How to restrict to run commands in specific directory through SUDOERS?
I can run chown and chmod commands by sudo system-wide, but want to run these commands in only /var/www/html directory.
How can restrict commands to run only in specified directory by sudo ...
5
votes
1answer
3k 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 ...
5
votes
4answers
1k views
Allow users to run only specific binaries with root permissions/privileges
I would like to allow a specific user to be able to sudo /sbin/iptables only.
I have a bash script which configures iptables. The problem is that configuring /sbin/iptables as sudoable is not enough ...
5
votes
1answer
746 views
how to set the sftp -s subsystem option in a configuration file
The sftp command supports a subsystem option (-s) which allows the remote user to select the remote sftp-server executable, and optionally upgrade to sudo in the process like so;
sftp -s ...
