This simple and brief tutorial will show you how to convert epub files to pdf files using calibre in Ubuntu.
1.Open a terminal by pressing CTL+ALT+t
2.Run below command in your terminal to install Calibre,input your password if prompted
sudo apt-get install calibre
3.After the installation finished ,launch Calibre from Dash
4.Then click Add books to add your epub file ,then click Convert books
5.Select PDF as Output format:
6.Done and you can find the pdf file under ~/Calibre Libary/