How to convert an epub file to pdf from the command line? I want to convert a few .epub files into .pdf files (no merge, just convert file_1.epub to file_1.pdf, file_2.epub to file_2.pdf, ...) and was wondering if there was a way to streamline the process using the Mac command line.

Heard about the Calibre application but this is not what I am looking for as I want to use the command line.
Calibre has a command line interface, see this part of the manual. Basically you should be able to add /Applications/calibre.app/Contents/MacOS to your PATH (or symlink the binaries there into /usr/local/bin) and then run 

ebook-convert input_file output_file