Question: how to install qdirstat ubuntu?
Answer: Ubuntu. sudo apt install qdirstat.
Debian. sudo apt-get install qdirstat.
Arch Linux. Fans of Arch can install Qdirstat through the AUR if they want to use it, as the developers don't officially support it. ... 
Fedora. sudo dnf install qdirstat -y.
OpenSUSE. sudo zypper install qdirstat.
Generic Linux.