listings does not ignore comment character inside a string

Question

I'm trying to insert a matlab code file in my tex document using listings but the output is messy because I'm using % inside a string with fprintf which is also a comment character.

In the line fprintf("ess = %.2f%%\n", ess); as soon as the % is read, everything (till the of the line) after it, is considered as a comment.

Here is a MWE:

\documentclass[english]{article}
\usepackage{color}
\usepackage{listings}
\definecolor{mycomment}{rgb}{0.63,0.63,0.65}
\definecolor{mygray}{rgb}{0.02,0.68,0.72}
\definecolor{mymauve}{rgb}{0.77,0.64,0.2}
\definecolor{mykw}{rgb}{0, 0.6, 0.87}
\definecolor{myblack}{rgb}{0.22,0.23,0.26}
\definecolor{myred}{rgb}{0.84,0.15,0.33}
\definecolor{mynumber}{rgb}{0.81,0.2,0.75}
\definecolor{row_hl}{rgb}{0.72,0.93,0.99}
\lstset{
    language=Matlab,
    backgroundcolor={\color{white}},
    basicstyle={\footnotesize\ttfamily},
    breakatwhitespace=false,
    breaklines=true,
    captionpos=b,
    commentstyle={\color{mycomment}\small},
    deletekeywords={...},
    escapeinside={"}{")},
    extendedchars=true,
    firstnumber=1,
    frame=tb,
    keepspaces=true,
    keywordstyle={\color{mykw}},
    morekeywords={tf,step,stepinfo,damp,factorial,poissrnd,normpdf,normcdf},
    numbers=left,
    numbersep=5pt,
    numberstyle={\tiny\color{mygray}},
    rulecolor={\color{black}},
    showspaces=false,
    showstringspaces=false,
    showtabs=false,
    stepnumber=1,
    stringstyle={\color{mymauve}},
    tabsize=2,
    title={\lstname}
}
\begin{document}
    % \lstinputlisting[caption={Matlab code.},label={lst:matlab-code}]{mod_sys_code.m}
\begin{lstlisting}
    fprintf(&quot;ess = %.2f%%\n&quot;, ess);
    fprintf(&quot;ess = should look like this\n&quot;);
\end{lstlisting}

\end{document}

Is there a workaround to solve this issue?

Please add a full minimal working example (MWE). You added your output, please be specific about, what's wrong with it. — MaestroGlanz, May 23 '22 at 07:11
Lstlistings doesn't know the language Matlab. If you change the language to bash, it is displayed correctly. — MaestroGlanz, May 23 '22 at 07:47
Unfortunately, I couldn't find out, how to add a language or correct it. — MaestroGlanz, May 23 '22 at 07:49
Thank you that fixed the bit within a string but it creates the issue where comments aren't detected. It's a good start, so I'll try to find something to include the comments. — Midouj, May 23 '22 at 08:50
You should figure out, how to teach lstlistings a new language. Or, if there is a language, with almost identical syntax, pick that one. I'm not proficient enough in Matlab to figure that out. — MaestroGlanz, May 23 '22 at 08:53
@MaestroGlanz, I've got it working with the language set to Matlab. I simply had to replace double quotes with single quotes. Thank you — Midouj, May 23 '22 at 09:18
@Midouj have you checked https://tex.stackexchange.com/questions/75116/what-can-i-use-to-typeset-matlab-code-in-my-document ? — Rmano, May 23 '22 at 09:22
Then you should add an answer to your own question for any future roamer looking for the solution. — MaestroGlanz, May 23 '22 at 09:25
@Rmano I tried matlab-prettier but it is a wrapper for listings so the initial problem remains the same. — Midouj, May 23 '22 at 09:27

score 1 · Answer 1 · answered May 23 '22 at 09:32

1

So to fix this issue I had to replace the double quotes (") used in the fprintf command with single quotes (').

answered May 23 '22 at 09:32

Midouj

21

score 0 · Answer 2 · answered May 23 '22 at 09:35

The package matlab-prettifier works if you use ' as a string delimiter.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[numbered,framed]{matlab-prettifier}
\lstset{
  style              = Matlab-editor,
  basicstyle         = \mlttfamily,
}
\begin{document}
    % \lstinputlisting[caption={Matlab code.},label={lst:matlab-code}]{mod_sys_code.m}
\begin{lstlisting}
    fprintf('ess = %.2f%%\n', ess);
    fprintf('ess = should look like this\n');
\end{lstlisting}

\end{document}

I do not know if there is an option for making it do the same with the " delimiter... you can try to ask on GitHub.

listings does not ignore comment character inside a string

2 Answers2