epubcheck software package provides Validation Tool for EPUB, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install epubcheck
epubcheck is installed in your system.
Make ensure the epubcheck package were installed using the commands given below,
$ sudo dpkg-query -l | grep epubcheck *
You will get with epubcheck package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Text Processing |
| Package | epubcheck |
| Version | 4.0.1-2 |
| Description | Validation Tool for EPUB |
| Sub Section | Text |