Boldface and subscripts in verbatim mode?

Question

How do I create boldface and subscripts in verbatim mode? I've seen mention of a fancyvrb package that might be able to help. Can anyone provide working LaTeX code, either with or without fancyvrb?

Answer 1

Using the fancyvrb package, with the commandchars option you can introduce escape sequences in verbatim code; in particular, you can get boldfaced fonts (provided you are using a suitable font. Using the codes option you can specify catcode changes ; in particualr, this allows you to include formatted mathematics in verbatim text:

\documentclass{article}
\usepackage{fancyvrb}
\usepackage{bera}

\begin{document}

\begin{Verbatim}[commandchars=\\\{\},codes={\catcode`$=3\catcode`_=8}]
code line 1
$a_{i}$
code line 2
\textbf{boldfaced text}
\end{Verbatim}

\end{document}

Using the more powerful listings package, you can escape to LaTeX using the escapeinside option and you can activate the mathescape option:

\documentclass{article}
\usepackage{listings}
\usepackage{bera}

\lstset{basicstyle=\ttfamily,
escapeinside={||},
mathescape=true}

\begin{document}

\begin{lstlisting}
code line 1
$a_{i}$
code line 2
|\textbf{boldfaced text}|
\end{lstlisting}

\end{document}

The above solutions treted subscripts as mathematical expressions; you can get non-math subscripts using \textsubscript from the fixltx2e package; a little example using fancyvrb:

\documentclass{article}
\usepackage{fancyvrb}
\usepackage{fixltx2e}
\usepackage{bera}

\begin{document}

\begin{Verbatim}[commandchars=\\\{\},codes={\catcode`$=3\catcode`_=8}]
code line 1
$a_{i}$
code line 2
\textbf{boldfaced text}
a\textsubscript{i}
\end{Verbatim}

\end{document}