Printable diffs

February 3, 2017

At Oxford we submit almost all of our practical assignments on paper, which usually means printing out the diff of the work that we’ve done. Generally most people just generate the diff with git and send it to the printer with lpr, but I’m yet to succeed at getting output that I like with this approach.

Therefore I am now generating the diff, saving it to a file, and then using the LaTeX listings package to produce line-wrapped, coloured output.

Firstly, I generate the diff file itself:

git diff ORIGINAL_COMMIT_HASH -- > all.diff

Then I generate a PDF via xelatex diff.tex from the following LaTeX file:

\documentclass[11pt,]{article}
\usepackage[margin=1in]{geometry}
\usepackage{listings}
\usepackage{parskip}
\usepackage[rgb,dvipsnames]{xcolor}

\definecolor{mygreen}{rgb}{0.1,0.25,0.01}
\definecolor{myred}{rgb}{0.25,0.1,0.01}
\definecolor{mymagenta}{rgb}{0.5,0.05,0.25}

\lstdefinelanguage{diff}{
  morecomment=[f][\color{blue}]{@@},       % group identifier
  morecomment=[f][\color{myred}]-,         % deleted lines
  morecomment=[f][\color{mygreen}]+,       % added lines
  morecomment=[f][\color{mymagenta}]{---}, % Diff header lines (must appear after +,-)
  morecomment=[f][\color{mymagenta}]{+++},
}

\lstset{
    basicstyle=\ttfamily,
    numberstyle=\footnotesize,
    stepnumber=1,
    numbersep=5pt,
    backgroundcolor=\color[RGB]{255,255,255},
    showspaces=false,
    showstringspaces=false,
    showtabs=false,
    tabsize=2,
    captionpos=b,
    breaklines=true,
    breakatwhitespace=true,
    breakautoindent=true,
    escapeinside={\%*}{*)},
    linewidth=\textwidth,
    basewidth=0.5em,
}

\begin{document}

\lstinputlisting{all.diff}

\end{document}

♦