This article covers how you can list installed packages on Ubuntu 20.04 LTS system. Also, you can also filter a specific package from the list and count the number of installed packages on your system.
You can list all installed packages with apt command or apt-get command on Ubuntu Linux.
You need to use the apt or apt-get or dpkg command to list all installed packages on an Ubuntu Linux server from the bash shell prompt.
To see what packages are installed on Ubuntu Linux:
1. Open the terminal application or log in to the remote server using ssh (e.g. ssh user@sever-name).
2. Run command apt list --installed to list all installed packages on Ubuntu.
3. To display a list of packages satisfying certain criteria such as show matching apache2 packages, run apt list apache.
To List all installed packages only:
The apt command displays both installed and packages available to install:
$ apt list --installed
To list or find out if a specific package installed or not:
Run package policy as follows:
$ apt list -a pkgNameHere