Question

How do I center text within a listing in Latex?

Or another way not using listing. (Need a box with monospace font)

Answer 1

The answer given at tex.stackexchange is:

\documentclass{article}
\usepackage{listings}
\renewcommand{\figurename}{Listing}
                    % replace figurename with the text that should preceed the caption
\begin{document}

\begin{figure}[thp] % the figure provides the caption
\centering          % which should be centered
\caption{Ausgabe des C-Programms}
\begin{tabular}{c}  % the tabular makes the listing as small as possible and centers it
\begin{lstlisting}[label={gtt_c_ausgabe}]
printf("Your code goes here.\n");
\end{lstlisting}
\end{tabular}
\end{figure}

\end{document}

…which still leaves me wondering:

Using a frame around the code, e.g. using \lstset{frame=single,frameround=tttt}, places the frame way over to the right. How can this be avoided?

What does the renewcommand bit do?