Today, I needed a terminal solution to merge different PDF files into a single file.
You can use the tool pdfunite from the poppler package to do this.
First, you need to install it. This depends a little on the platform you are using:
Install on mac
$ brew install poppler
Install on Ubuntu Linux
$ sudo apt install poppler-utils
After the install, you can inspect how it works by running it's help command:
$ pdfunite -?
pdfunite version 20.11.0
Copyright 2005-2020 The Poppler Developers - http://poppler.freedesktop.org
Copyright 1996-2011 Glyph & Cog, LLC
Usage: pdfunite [options] <PDF-sourcefile-1>..<PDF-sourcefile-n> <PDF-destfile>
-v : print copyright and version info
-h : print usage information
-help : print usage information
--help : print usage information
-? : print usage information
So, we can easily combine PDF files now using:
$ pdfunite pdf1.pdf pdf2.pdf combined_pdf.pdf
Thanks to StackOverflow for helping me finding this out :)