"Listing #" below listings without a caption

Question

When not specifying a caption for a lstlisting nothing is shown below the listing while "Listing #: mycaption" is displayed as soon as I specify a caption.

However, I'd like "Listing #" to be displayed for all listings; even those without a caption (those with a caption should keep their "Listing #: mycaption" of course). Is this possible? If yes, how?

Answer 1

You can use caption=\relax; however, then you'll get "Listing #:" with the colon. I don't know how to remove this.

EDIT: OK, here's a nasty hack that removes the colon if the caption is \relax. It works with my version of listings, but it might not work in future versions.

\documentclass{article}
\usepackage{listings}
\begin{document}
\makeatletter
\def\test@relax{\relax}
\let\save@fnum@lstlisting\fnum@lstlisting
\def\fnum@lstlisting{%
    \save@fnum@lstlisting
    \ifx\lst@caption\test@relax\expandafter\@gobble\fi
    }
\makeatother
\begin{lstlisting}[caption=\relax]
a:=b
\end{lstlisting}
\end{document}

Answer 2

My idea is everything else than a nice solution but here you go:

\newcommand\emptytitle{\lstlistingname\ \thelstlisting}
\newcommand\nextlst{\addtocounter{lstlisting}{1}}

\begin{lstlisting}[language=C,title=\emptytitle]
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    printf("Hallo Welt!\n");
    return EXIT_SUCCESS;
} /* end main() */
\end{lstlisting}

\nextlst
\begin{lstlisting}[language=C,title=\emptytitle]
#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    printf("Hallo Welt!\n");
    return EXIT_SUCCESS;
} /* end main() */
\end{lstlisting}

Btw. \newcommand\emptytitle{\lstlistingname\ \thelstlisting \nextlst} does not work because somehow the counter makes +2 jumps.

Answer 3

My workaround was to pass this title argument

title={\lstlistingname\space\thelstlisting}

to each listing. This very tedious, but I'm using Lyx, so it's relatively simple to just copy listings arounds.