---
myst:
  html_meta:
    keywords: LaTeX,formatting,formater un programme,formater du code,verbatim,insérer du code-source"
---
# Code listings in LaTeX

"Pretty" code listings are sometimes considered worthwhile by the "ordinary" programmer, but they have a serious place in the typesetting of dissertations by computer science and other students who are expected to write programs. Simple verbatim listings of programs are commonly useful, as well.

[Verbatim listings](/4_domaines_specialises/informatique/inclure_un_fichier_en_mode_verbatim) are dealt with elsewhere, as is the problem of [typesetting algorithm specifications](/4_domaines_specialises/informatique/ecrire_du_pseudocode).

The <ctanpkg:listings> package is widely regarded as the best bet for formatted output (it is capable of parsing program source, within the package itself), but there are several well-established packages that rely on a pre-compiler of some sort. You may use <ctanpkg:listings> to typeset snippets that you include within your source :

```
\documentclass{article}
\usepackage{lmodern}
\usepackage{listings}
\lstset{language=C}
\begin{document}
\thispagestyle{empty}
\begin{lstlisting}
#include <stdio.h>

int main(int argc, char ** argv)
{
  printf("Hello world!\n");
  return 0;
}
\end{lstlisting}
\end{document}
```

or you can have it typeset whole files :

```{noedit}
\usepackage{listings}
\lstset{language=C}
...
\begin{document}
\lstinputlisting{main.c}
\end{document}
```

These very simple examples may be decorated in a huge variety of ways, and of course there are other languages in the package's vocabulary than just `C`...

For a long time, advice on (La)TeX lists seemed to regard <ctanpkg:listings> as the be-all and end-all on this topic. In the last few years, viable alternatives have appeared

`Highlight` is attractive if you need more than one output format for your program : as well as (La)TeX output, `highlight` will produce (X)HTML, RTF and XSL-FO representations of your program listing. The manual leads you through the details of defining a parameter file for a "new" language, as well as the presentation details of a language.

The <ctanpkg:minted> package is another alternative that offers the means of creating new language definitions. It requires that code be processed using an external (`python`) script, [`Pygments`](https://pygments.org/). Pygments, in turn, needs a "lexer" that knows the language you want to process; lots of these are available, for the more commonly-used languages, and there is advice on "rolling your own" on the [`Pygments` website](https://pygments.org/docs/lexerdevelopment/).

Usage of <ctanpkg:minted> can be as simple as

```{noedit}
\begin{minted}{⟨language⟩}
...
\end{minted}
```

which processes the program code dynamically, at typesetting time --- though such usage is likely to require that [separate processing be enabled](/2_programmation/compilation/write18).

On a rather different path, the package <ctanpkg:showexpl> supports typesetting (La)TeX code and its typeset output, in parallel "panes". (This could provide support for (La)TeX instruction texts, or for papers in TeX user group publications. The package uses <ctanpkg:listings> for its (La)TeX pane, and typesets the result into a simple box, for the other pane.

Longer-established, and variously less "powerful" systems include :

- The `lgrind` system is a well-established pre-compiler, with all the facilities one might need and a wide repertoire of languages; it is derived from the even longer-established `tgrind`, whose output is based on Plain TeX.
- The `tiny_c2l` system is slightly more recent : users are again encouraged to generate their own driver files for languages it doesn't already deal with, but its "tiny" name correctly hints that it's not a particularly elaborate system.
- The `C++2LaTeX` system comes with strong recommendations for use with `C` and `C++`.
- An extremely simple system is `c2latex`, for which you write LaTeX source in your `C` program comments. The program then converts your program into a LaTeX document for processing. The program (implicitly) claims to be "self-documenting.

:::{sources}
[Code listings in LaTeX](faquk:FAQ-codelist)
:::