Concatenate/Combine PDF Files in Linux

I know there are lots of ways to do this. This is not a HOW-TO, but just sharing a script I made for doing this. It's a decent example of how to write a command-line utility in Python.

Since I write my cover letters and resumes in LaTeX I always need to concatenate the two together before sending it to an employer. This is very important so that the person on the other end prints out both and it makes their life easier by not having to worry about two files. For the longest time I just had a simple script that looked like this:

#!/bin/sh
#Concatenate two PDF files and output to the third argument
echo "**** Converting PDF files to PostScript"
acroread -toPostScript -size letter -pairs $1 /tmp/$1.ps
acroread -toPostScript -size letter -pairs $2 /tmp/$2.ps
 
echo "**** Concatenating PostScript files"
a2ps -q --columns=1 -o /tmp/$1.both.ps /tmp/$1.ps /tmp/$2.ps
 
echo "**** Converting PostScript file to PDF"
ps2pdf /tmp/$1.both.ps $3
 
echo "**** File saved to:" $3
 
echo "**** Cleaning up"
rm -f /tmp/$1.ps
rm -f /tmp/$2.ps
rm -f /tmp/$1.both.ps

I am just including that code because it shows clearly what is going on. The input PDF files are converted to Postscript files using acroread, the Postscript files are concatenated using a2ps, then the output Postscript file s converted to PDF using ps2pdf.

I decided to make it in to a full-blown Python script since I don't know bash/sh very well and I wanted it to be able to handle errors and an unlimited number of input files. There was a case in the past where I had to concatenate more than two input files, which involved running this script multiple times. I know there are many other simpler ways of doing this but I wanted to get more practice writing a unix command line utility in python using subprocess and optparse (and making the file importable so it can be used by other scripts, which many people forget to do). The script is a lot more complicated now but it's so much better functionality-wise. Enjoy!