The dpkg command can be used to list all installed packages. I wanted to list the language packs installed with Firefox. So the command below is perfect.
jason@Yog-Sothoth:~$ dpkg --list firefox-locale-* Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-==============================-====================-====================-================================================================== ii firefox-locale-de 75.0+build3-0ubuntu0 amd64 German language pack for Firefox ii firefox-locale-en 75.0+build3-0ubuntu0 amd64 English language pack for Firefox ii firefox-locale-es 75.0+build3-0ubuntu0 amd64 Spanish; Castilian language pack for Firefox ii firefox-locale-fr 75.0+build3-0ubuntu0 amd64 French language pack for Firefox ii firefox-locale-it 75.0+build3-0ubuntu0 amd64 Italian language pack for Firefox ii firefox-locale-pt 75.0+build3-0ubuntu0 amd64 Portuguese language pack for Firefox ii firefox-locale-ru 75.0+build3-0ubuntu0 amd64 Russian language pack for Firefox ii firefox-locale-zh-hans 75.0+build3-0ubuntu0 amd64 Simplified Chinese language pack for Firefox |
Another example, I am listing all packages that match for the word chrome.
jason@Yog-Sothoth:~$ dpkg --list chrom* Desired=Unknown/Install/Remove/Purge/Hold | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad) ||/ Name Version Architecture Description +++-==============================-====================-====================-================================================================== rc chrome-gnome-shell 10-1 all GNOME Shell extensions integration for web browsers un chromedriver <none> <none> (no description available) un chromium <none> <none> (no description available) ii chromium-browser 81.0.4044.122-0ubunt amd64 Chromium web browser, open-source version of Chrome un chromium-browser-inspector <none> <none> (no description available) ii chromium-browser-l10n 81.0.4044.122-0ubunt all chromium-browser language packages un chromium-codecs-ffmpeg <none> <none> (no description available) ii chromium-codecs-ffmpeg-extra 81.0.4044.122-0ubunt amd64 Extra ffmpeg codecs for the Chromium Browser un chromium-driver <none> <none> (no description available) |
This is how to get the version of an installed package.
jason@Yog-Sothoth:~$ dpkg -s firefox | grep Version | cut -d" " -f2 75.0+build3-0ubuntu0.18.04.1 |
This is a very useful Linux tip.
Count the number of installed packages.
jason@Yog-Sothoth:~$ dpkg --list mate* | wc -l 82 |
This shows that I have 82 packages installed for the MATE desktop. This shows that dpkg is very useful to know about when using Debian or Ubuntu. It can list all packages installed with something like Firefox and list all language packs that you have installed. Very useful information when you wish to remove some of them and you need to know which are actually installed on your system.