Install susv4 by entering the following commands in the terminal:
sudo apt update sudo apt install susv4
Description:
Fetch and install SUSv4 (POSIX.1-2008)
The Single Unix Specifications are not permitted to be generally redistributed, so this is an installer that fetches them and installs them in a Debian appropriate way. This installer will fetch and install POSIX:2008 (also known as Single Unix Specification v4) with POSIX:2013 Technical Corrigendum 1 and POSIX:2016 Technical Corrigendum 2.
Version: 7.20161013
Section: multiverse/doc