How to check if some program is already installed and its version?

Question

I'm exploring working with the ubuntu terminal. For particular reason I need to check if I have installed Python interpreter, like cPython. How to do it? In general, how to check if some program is already installed and its version?

Just do sudo apt-get install <package>? – Tim Jul 17 '14 at 18:53 — Tim, Jul 17 '14 at 18:53

score 4 · Answer 1 · answered Jul 17 '14 at 19:41

4

You can get a list of all installed packages with

dpkg --get-selections

to get more info about a package try

dpkg -s <PACKAGENAME>

answered Jul 17 '14 at 19:41

Ruediger

2,182

score 4 · Answer 2 · edited Jun 12 '20 at 14:37

4

You can try these.

By which

which <packagename>

Example: which firefox

Correct Result: /usr/bin/firefox

By dpkg

dpkg -l | grep <packagename>

Example: dpkg -l | grep firefox

Correct Result: ii firefox 22.0+build2-0ubuntu0.12.04.2 Safe and easy web browser from Mozilla

Illustration

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edited Jun 12 '20 at 14:37

Community

1

answered Jul 17 '14 at 19:51

Ade Malsasa Akbar

637

score 2 · Answer 3 · answered Jul 17 '14 at 20:01

2

To know the version of an installed package just use the dpkg-query command:

$ dpkg-query -W foo
dpkg-query: no packages found matching foo
$ dpkg-query -W unity
unity   7.2.0+14.04.20140423-0ubuntu1.2

answered Jul 17 '14 at 20:01

Sylvain Pineau

62,169

@PeterMortensen Indeed, only the version string can tell if the package is installed or not, good point. Thanks – Sylvain Pineau Jul 19 '16 at 16:29

How to check if some program is already installed and its version?

3 Answers3

By which

By dpkg

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