Questions related to the sudo command that allows users to run programs with the privileges of a different user (normally the root user).

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13
votes
7answers
2k views

Nothing shows up in the terminal when I type my password

When I'm about to install a program in the terminal it wants the password: [sudo] password for xxx: But when I want to type my password it happens nothing. What should I do?
57
votes
8answers
17k views

How to avoid using sudo when working in /var/www?

I want to stop having to use sudo everytime I work in /var/www. How can I do that? I simply want to put all of my sites into this directory and work with them without too much pain.
18
votes
3answers
11k views

How do I add myself back as a sudo user?

I clean-installed Ubuntu 11.10 today, and then installed VirtualBox. This required me to add myself to the vboxusers group, and since 11.10 seems to no longer have a graphical app to add users to a ...
44
votes
9answers
19k views

What is the difference between “gksudo nautilus” and “sudo nautilus”?

I've been using gksudo nautilus and sudo nautilus through Alt+F2. What's the difference? They look very similar!
185
votes
6answers
511k views

How can I add a new user as sudoer using the command line?

After I add a user using adduser, I can't see it via System->Administration->Users and Groups unless I logout and then login again. Is that normal? Also, can I set a newly added user as a ...
60
votes
11answers
70k views

How to modify a invalid /etc/sudoers file? It throws out an error and not allowing me to edit again

How do I edit an invalid visudo file? Here is what happens: $ sudo visudo >>> /etc/sudoers: syntax error near line 28 <<< sudo: parse error in /etc/sudoers near line 28 sudo: no ...
27
votes
4answers
47k views

Difference between “su”, “sudo -s”, “sudo -i”

I already read it from manual but I can't see difference.. su - change user ID or become superuser sudo -s [command] The -s (shell) option runs the shell specified by the SHELL environment ...
17
votes
3answers
5k views

sudo & redirect output

I have a small question regarding using sudo with output redirect >. To enable IP forwrding, someone can use the command: echo 1 > /proc/sys/net/ipv4/ip_forward Executing this command will ...
34
votes
1answer
37k views

How do I run specific sudo commands without a password?

On one particular machine I often need to run sudo commands every now n then. I am fine with entering password on sudo in most of the cases. However there are three sudo commands I want to run ...
60
votes
4answers
64k views

How do I sudo a command in a script without being asked for a password?

I want to turn my system on automatically every day. So I use the below code in my Python script, but sudo asks me for a password every time: os.system('sudo sh -c "echo date \'+%s\' -d \'+ \ ...
55
votes
5answers
94k views

How do I add a user to the “sudo” group?

In /etc/sudoers I see this: # Allow members of group sudo to execute any command after they have # provided their password # (Note that later entries override this, so you might need to move # it ...
31
votes
2answers
3k views

Why user should never use normal sudo to start graphical application?

I've read the comunity "RootSudo" documentation and am interested in this line: You should never use normal sudo to start graphical applications as Root. Why? What is the difference? Please ...
16
votes
6answers
23k views

How to run an application using sudo without a password?

... but still be required for applications that need admin privilegies? In order to allow the following: $ apache2ctl restart httpd not running, trying to start (13)Permission denied: make_sock: ...
10
votes
4answers
3k views

What if I accidently run command “chmod - R” on system directories (/, /etc, …)

I accidently ran sudo chmod 755 -R / instead of sudo chmod 755 -R ./ I stopped it after few seconds, but now there is some problems such as sudo: must be setuid root How can I revert ...
5
votes
4answers
31k views

'Some index files failed to download' while updating

When running sudo apt-get update I get these following errors: Err archive.ubuntu.com quantal InRelease Err archive.ubuntu.com quantal-updates InRelease Err archive.ubuntu.com quantal-backports ...
8
votes
3answers
19k views

Mount VirtualBox SharedFolder in Ubuntu VM on boot

I have a Ubuntu VM running in VirtualBox. I have a Shared Folder set up as myshare I have a folder created in my home directory (~/jamesw) as host. using the line sudo mount -t vboxsf myshare host ...
45
votes
8answers
54k views

Error message when I run sudo: unable to resolve host (none)

I have this issue on AWS on some servers. Whenever I run sudo the terminal is stuck doing seemingly nothing, until it finally spits out this error message. My terminal looks like this: ...
8
votes
6answers
4k views

What are the benefits of sudo over su?

What is the actual benefit that ubuntu (or debian derivatives) achieve by disabling root user. Everywhere I read, its says to prevent unintentional damages for inexperienced users. I want to know ...
38
votes
3answers
6k views

When to use pkexec vs. gksu/gksudo?

There are two general ways to run applications graphically as root (or, more generally, as another user). Programs like gksu, gksudo, and kdesudo are graphical frontends for sudo. In contrast, pkexec ...
26
votes
5answers
5k views

How to NOT become a root user? Are administrators root?

I installed Ubuntu on my PC. To log in, I use the username and password I created during installation. Does this mean I am a root user? If yes, then how do I become non-root? It looks like non-root ...
8
votes
4answers
109k views

How do I login as root?

I want to login as root, but when I enter sudo -s and enter password, this message is shown: "you are not in sudoers file", and when I enter su and enter password, this is shown: ...
7
votes
3answers
9k views

How to fix sudo after “chmod -R 777 /usr/bin”?

I enetered chmod -R 777 /usr/bin and now sudo is not working. It is giving error that sudo must be setuid root. On looking via Google, some advice said to run chown root:root /usr/bin/sudo chmod ...
10
votes
6answers
3k views

Why can't non-admin users install software?

This is probably something I don't understand since I am used to Windows and am only starting out with Ubuntu. I know that software in linux comes in packages what I don't understand is why can't ...
5
votes
2answers
4k views

Regain Sudo rights after removing from admin group [duplicate]

I accidentally removed myself from the admin group when editing the user. Now I can no longer use sudo. The error says: ber is not in the sudoers file. This incident will be reported. I booted up ...
14
votes
3answers
12k views

Shutdown from terminal without entering password?

I have desktop edition of Ubuntu. I like the Terminal so that that I prefer to shutdown my computer with the shutdown command. However when I type shutdown now it prompts me to enter my password.Is ...
15
votes
4answers
5k views

su command + authentication failure

I am having problems with the su command. I know my password and I am typing it correctly but su indicates authentication failure. So I checked on the internet and then went into recovery mode and ...
35
votes
3answers
4k views

What are the differences between sudo, su, visudo, chroot, and gksu?

What are the differences between sudo, su, visudo, chroot, and gksu ?
38
votes
4answers
12k views

What is the difference between the 'sudo' and 'admin' group?

I noticed that two groups are granted similar-looking permissions in /etc/sudoers: # Members of the admin group may gain root privileges %admin ALL=(ALL) ALL # Allow members of group sudo to execute ...
7
votes
6answers
9k views

How can I run an application with a GUI as super user from a normal user session?

I defined 2 users: one with admin privilege (lets call it admin) with sudo right. a 2nd one without any privilege (lets call it normaluser) and I configure the autologin on this 2nd user normaluser. ...
7
votes
3answers
2k views

sudoers - simple explanation requested

Everytime I want to be able to run something that requires me to be a sudoer too many times, I need to google for the formatting of /etc/sudoers to remind me again what exactly is the proper way to ...
23
votes
6answers
27k views

sudo error, is mode 0777, should be 0440

I am getting sudo errors, how do I fix this error? sudo: /etc/sudoers is mode 0777, should be 0440 sudo: no valid sudoers sources found, quitting
6
votes
2answers
14k views

Setting the PATH so it applies to all users, including root/sudo

The instructions in How do I set PATH variables for all users on a server? work to set the PATH for all 'normal' users. However, if I do sudo -s and then printenv PATH the updated path is not shown. ...
28
votes
4answers
44k views

Execute sudo without Password?

Inspired by this question.... I am the sole person using my system with 12.04. Every time I issue a sudo command; the system asks for the user password (which is good in its own way). However I was ...
19
votes
4answers
91k views

How do I grant sudo privileges to an existing user? [duplicate]

I want to grant a newly created user sudo privileges in Ubuntu. I tried sudo adduser hduser admin but it says no admin group exists. How can I do it?
33
votes
4answers
3k views

Why do we need to be root in terminal for shutdown and restart?

When we install/remove/update packages or make any changes which require administrative privileges we are prompted for the password of admin user who has the sudo privileges - this happens both via ...
12
votes
2answers
7k views

How do I prevent PolicyKit from asking for a password?

For years, I've had the following in my sudoers file: scott ALL=NOPASSWD: ALL For those who don't know, this prevents sudo and friends (gksudo, etc.) from asking for a password. However, over the ...
5
votes
3answers
14k views

Password not working for sudo (“Authentication failure”)

Before I mention anything further, DO NOT give me a response saying that terminal won't show password input. I'm AWARE of that. I'm typing my user password in (not a capslock issue), and for some ...
3
votes
2answers
792 views

How can I re-instate my admin privileges?

I am running 12.04 LTS. It's a pretty default installation and is the only OS on this machine. I have two users one has administrator rights the other does not. I accidentally removed administrator ...
31
votes
2answers
46k views

How to run sudo command with no password?

How does the ubuntu user on the AWS images for Ubuntu Server 12.04 have passwordless sudo for all commands when there is no configuration for it in /etc/sudoers? I'm using Ubuntu server 12.04 on ...
10
votes
3answers
4k views

How to prevent system applications (like the Software Center) from asking for password?

I'd like Software Center, Update Manager and some other system management applications to work without asking for password (like sudo does if configured with NOPASSWD) but only asking for a ...
10
votes
2answers
12k views

Environment variables when run with 'sudo'

As example to my question, my ~/.bashrc file contains this lines: > export LD_LIBRARY_PATH=/opt/intel/mkl/lib/ia32:$LD_LIBRARY_PATH > export LD_PRELOAD=/opt/intel/mkl/lib/ia32/libmkl_core.so ...
1
vote
2answers
563 views

Graphical authentication works; why does sudo say my password is wrong?

I'm trying to install a theme, and when I enter the command sudo cp -r $HOME/Desktop/Overglossed /usr/share/themes the terminal asked for my sudo password which I entered, however I'm told my password ...
13
votes
3answers
30k views

My main username is not in the sudoers file

I was trying to install some software/edit files with my main username(not root) But I got this error [X] is not in the sudoers file. This incident will be reported. I tried to edit the /etc/sudoers ...
4
votes
1answer
3k views

sudo does not ask for password

Whenever I issue command sudo apt-get install foo it does not ask for password. is it because of user groups? How to make it prompt for password? Edit: My sudoers file apple@Ascension:~$ sudo cat ...
2
votes
7answers
19k views

How can I determine the sudo password? [duplicate]

What is the default password of the sudo? I visit some forums, it tells that the default password is password, but it doesn't work, how can I determine the password?
66
votes
9answers
6k views

Run same command again but as sudo

Sometimes when I run a command I don't notice that I needed to run it as super user to have enough permission. Is there a way to run the same command again but as a super user?
18
votes
5answers
32k views

How to launch application as root from Unity Launcher?

Mainly I am looking for a way to pin an application to the Unity launch bar, and run it as root. Currently, even if I start the application with sudo, and pin it after it starts, it will start as ...
16
votes
4answers
5k views

Is the difference between sudo and gksu the same as the difference between sudo -i and sudo -s?

Is the difference between sudo cmd and gksu cmd, the same as the difference between starting a shell with sudo -i and sudo -s? ... or put another way, Is sudo cmd the same as sudo -i cmd and gksu ...
12
votes
3answers
2k views

How to cancel the currently-applied remaining sudo time-out?

When I've just run sudo, and don't want it to remain active for the normal duration of its time-out, how can I cancel that remaining active time-out? sudo -k kills it for the current terminal ...
9
votes
3answers
18k views

Disable sudo permission to user from command line

I have activated root user in ubuntu and want to use ubuntu as server with no DE. For this I want to disable sudo privilege given to first user. How can I do this from command line ? I know I can use ...