Use textit in listing

Question

How can I use \textit in a listing?

\documentclass[a4paper]{article}

\begin{document}

\begin{lstlisting}[label=test]
Some code.
\textit{This should be italic.}
Some code.
\end{lstlisting}

\end{document}

Answer 1

You can emphasize words using the emph and emphstyle keys. See page 19 in the listings manual.

\documentclass[a4paper]{article}

\usepackage{listings}

\begin{document}

\lstset{emph={world}, emphstyle=\itshape} % the word "world" shall be italic
\begin{lstlisting}[label=test]
   Hello world
\end{lstlisting}

\end{document}

I agree, it is not a good solution for highlighting single lines of code. I think here is what you are looking for:

\documentclass[a4paper]{article}

\usepackage{listings}
\lstset{escapeinside={(*@}{@*)}}

\begin{document}

\begin{lstlisting}[label=test]
Some code.
(*@\textit{This should be italic.}@*)
Some code.
\end{lstlisting}

\end{document}