# Doing PDF Diff (using Alpine on Docker) The program will make a comparison of 2 PDF files, and highlight the differences into png image file. ## Start docker container Let's start the alpine and put it into background. The name for the container will be *alpine-pdf-diff*. Make sure you run in the folder that you want the PDF files to be compared. And it will mount to /pdf folder in the Alpine. docker run --name alpine-pdf-diff -dt -v `pwd`:/pdf -w /pdf junyong/pdf-diff Change *`pwd`* to "%CD%" if you are running in windows environment. Using terminal that comes with the Docker toolbox is fine with `pwd`. ## Use PDF diff to compare 2 PDFs Go to the folder (stated above) that run the container. Now, let's say you want to compare RR-16898.pdf and RR-16900.pdf, run the following docker exec alpine-pdf-diff pdf-diff RR-16898.pdf RR-16900.pdf > diff.png diff.png will be generated in the current folder. Just open to view it, the difference will be highlighted using red color line or box.