-1

A program called python-netifaces (0.8-3build1, automatic) installed without my installing it.

I was trying to install gufw on a standard account on a fully up to date, newly-installed Ubuntu 14.04.

Anyone know if this is abnormal or it's just supposed to be there even though I didn't explicitly install it?

5
  • 1
    I don't understand what you are trying to say, please explain better. What is the abnormal thing? Is gufw or not? Have you tried to install something?
    – Lucio
    May 22, 2014 at 1:05
  • 4
    python-netifaces is a dependency of gufw. When you install a program, all of it's dependencies will also install.
    – chaskes
    May 22, 2014 at 1:08
  • I was only trying to install gufw. I decided to check my history and I found that python-netifaces had been installed at the same time. I didn't try to install python-netifaces
    – user284050
    May 22, 2014 at 1:09
  • 4
    gufw depends on it. It can't function without it. It will install it every time.
    – chaskes
    May 22, 2014 at 1:10
  • 2
    If you plan to keep using a GNU environment, you should start reading. Specially what you see on a terminal.
    – Lucio
    May 22, 2014 at 1:44

2 Answers 2

5

Packages (programs) often require other programs to be installed in order for them to work. These other packages are called dependencies, because the first program depends on them being installed.

When you install a package, the dependencies will also be installed. This process is hidden from you when using the Software Center.

If you would like to know about the dependencies that will be installed, you can use the command line.

For example:

sudo apt-get install gufw
The following extra packages will be installed:
python-netifaces
The following NEW packages will be installed:
gufw python-netifaces
Need to get 482 kB of archives.
After this operation, 2,607 kB of additional disk space will be used.
Do you want to continue? [Y/n] 

You can then choose to cancel the installation if for some reason you do not wish to install the dependencies.

Other ways to look into the dependencies include:

apt-cache show gufw
Depends: python:any (>= 2.7.1-0ubuntu2), ufw (>= 0.31.1), gir1.2-gtk-3.0, policykit-1, gnome-icon-theme-symbolic, python-netifaces, gir1.2-webkit-3.0

Note that apt-cache shows all of the dependencies, while apt-get only shows the dependencies that are not yet installed.

You can also use the Ubuntu package database . See the results page for gufw .

1

You installed gufw , which has python-netifaces as a dependecy.

"Dependecies", as their name says, are package that are needed by another for it to work. You'll notice that if you try yo remove python-netifaces, gufw will uninstall itself at the same time.

From Linux Dictionnary :

Definition: dependencies: The proper functionality of one package may rely on the existence of another package, meaning there is a dependency [...]

From the wiki. :

When you install a program, its dependencies must be installed at the same time. Usually, most of the required dependencies will already be installed, but a few extras may be needed, too. So, when you install a package, don't be surprised if several other packages are installed too - these are just dependencies which are needed for your chosen package to function properly.

That's how Linux works.

Not the answer you're looking for? Browse other questions tagged .