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Ubuntu 13.04 – How to Change the Timout Period for sudo

richardsplanet — Wed, 01 May 2013 10:32:28 +0000

This tutorial is for Ubuntu 13.04.

It is probably the same for other versions of Ubuntu and (probably) most other Linux distributions, but no guarantee is made.

Detailed instructions for opening a command line / terminal can be found here.

By default, sudo temporarily grants administrative privileges for 15 minutes. This means the first time you run sudo you will be prompted for your password. Then, for the next 15 minutes, you can run sudo without having to re-enter your password.

This should be fine for most users because the average user probably rarely drops to a command line to run an administrative command or two.

1) Open a terminal using Ctrl + Alt + T:

2) Enter the following command:

sudo visudo

3) Enter your password:

Note: when you type your password, nothing will happen on the screen. This is normal. As a security feature, Linux does not echo back any indication of the characters you are typing in.

This will bring up the sudo configuration file in the nano editor. Note: in other versions of Linux (or if Ubuntu has been modified), the configuration file may be opened with a different editor – in which case, you will need to Google for instructions on using that editor.

The command visudo does more than just open the sudo configuration file with the nano editor. It also checks to ensure the configuration file is correct (i.e. it will not let you edit the file and make it invalid). Note: you can still edit the file, so sudo becomes unusable, but the configuration file is (technically speaking) valid.

4) Locate the line Defaults (highlighted in yellow) and navigate to the end of it using the arrow / cursor keys on your keyboard (your mouse will not work). Add the following:

,timestamp_timeout=0

The number tells sudo for many minutes it should grant administrator privileges in this session.

A value of 0 tells sudo to always prompt for a password. Personally, this is the only setting that makes sense for me because if you are momentarily away from your computer, no one else can accidentally (or intentionally) run an administrative command while your sudo privilege is still active.

A positive number tells sudo to grant administrative privileges that that number of minutes. The number must be a whole number: 5, 15, 42, etc. Number like 3.1415 are not valid.

A negative number tells sudo to permanently grant administrative privileges during that session. The only use I see for this is if you want to have to type sudo before administrative commands, but not have to enter the password for subsequent commands.

5) Save your changes by pressing Ctrl + O:

You will be prompted to save the file as /etc/sudoers.tmp.

6) Press Enter to write the changes.

7) Observe that the changes were written:

8) Exit visudo by pressing Ctrl + X.

Starting a new command line session should pick up the changes you just made.

The post Ubuntu 13.04 – How to Change the Timout Period for sudo appeared first on Complete, Concrete, Concise.

Ubuntu 12.04 – How to Change the Timeout Period for sudo

richardsplanet — Wed, 13 Mar 2013 11:25:43 +0000

This tutorial is for Ubuntu 12.04.

It should be the same for other versions of Ubuntu and (probably) most other Linux distributions, but no guarantee is made.

Detailed instructions for opening a command line / terminal can be found here.

By default, sudo temporarily grants administrative privileges for 15 minutes. This means the first time you run sudo you will be prompted for your password. For the next 15 minutes, you can run sudo without having to enter a password.

This should be fine for most users because the average user is likely to drop down to a command line to run an administrative command or two rarely.

1) Open a terminal using Ctrl + Alt + T

2) Enter the following command:

sudo visudo

3) Enter your password:

Note: when you type your password, nothing will happen on the screen. This is normal. As a security feature, Linux does not echo back any indication of the characters you are typing in.

4) Locate the line Defaults (highlighted in yellow) and navigate to the end of it using the arrow / cursor keys on your keyboard. Add the following:

,timestamp_timeout=0

The number tells sudo the number of minutes it should grant administrator privileges in this session.

A positive number tells sudo to grant administrative privileges that that number of minutes. The number must be a whole number: 5, 15, 42, etc. Number like 3.1415 are not valid.

5) Save your changes by pressing Ctrl + O:

You will be prompted to save the file as /etc/sudoers.tmp.

6) Press Enter to write the changes.

7) Observe that the changes were written:

8) Exit visudo by pressing Ctrl + X.

Starting a new command line session should pick up the changes you just made.

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Ubuntu 11.10 – Understanding sudo apt-get install …

richardsplanet — Tue, 01 Nov 2011 03:35:08 +0000

This tutorial is for Ubuntu 11.10, however, it should be the same for other versions of Ubuntu (and derivatives, like edubuntu, kubuntu, lubuntu, and xubuntu) and other Linux distributions based on Debian.

However, no guarantee is made.

What makes Ubuntu very easy to use is the Ubuntu Software Center which allows users an easy way to select and install or remove packages (usually programs).

However, when you search the web looking for help with Ubuntu, often times you see something to the effect of:

Enter the following command:

sudo apt-get install lubuntu-desktop

While this is clear for those who know what it means, I believe the majority of Ubuntu users are those who want a simple to install and use Linux OS – they are not interested in lower level details of managing their system.

In most cases, you can enter the package name into the Ubuntu Software Center and install it that way. For example, if you found the instructions: sudo apt-get install lubuntu-core and didn’t want to use apt-get you could enter lubuntu-core into the search field of Ubuntu Software Center and select the appropriate package from there.

Advantages of using apt-get

When you use the Ubuntu Software Manager, all the details of the installation are hidden from you – you don’t know if you are installing just one package or twelve.

Using apt-get, you can see which packages are going to be installed. This also makes it easier to know which packages to uninstall if you uninstall later.

A common complaint about Microsoft Windows is that applications often install a lot of junk that is not removed when the application is uninstalled. Ubuntu isn’t any better in this regard. This is because installers and uninstallers are hard to write – when you uninstall you don’t want to accidentally remove packages or files that some other application is using, so uninstallers tend to be conservative and leave stuff behind.

Another advantage of using apt-get instead of the Ubuntu Software Center is that apt-get allows you to install multiple packages with a single command. With the Ubuntu Software Center you need to install each package separately.

For example, if I want to install the astronomy packages Stellarium and Celestia GNOME using the Ubuntu Software Center, I need to install each separately. Using apt-get, I can install both from the same command by separating them with a space:

sudo apt-get install stellarium celestia-gnome

What it is

The command is really two commands:

sudo – a command to grant super user access to the system. Ubuntu is configured to prevent administrative (or system level) changes to the operating system. This is a security measure. sudo allows a user to temporarily override this behaviour.
apt-get – the Advanced Packaging Tool which allows users to install, remove, and update packages on their system.

Using apt-get

Instructions on how to open a terminal can be found here.

1) Type the command and press Enter (in this case, I am installing the package stellarium):

2) Type your password and press Enter. Note: as a security measure, your keystrokes are not echoed back to you. You will be typing, but see no feedback on the screen. While weird, this is normal.

3) Examine the install information (if you like):

The install information shows you the following:

Any extra packages that will be installed along with the selected package (yellow)
The list of packages to be installed this includes the package you are installing along with any extra packages needed (green)
A summary of (1) number of packages being upgraded, (2) number of new packages being installed, (3) number of packages being removed, (4) number of packages that are unaffected (red)
How large the download will be (blue)
How much disk space will be used by the installation (grey)

apt-get may display additional information, but, for this tutorial, it is not relevant.

4) If you want to go ahead with the installation, press Enter. If you changed your mind, type n (upper or lower case – it doesn’t matter) and press Enter,

5) Wait for the installation to finish. During installation, you will see downloading information and installation information:

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