Using \input inside environment fails

Question

I'm trying to use the filecontents package in combination with listings as suggested in How to define macro that only makes argument substitution? in order to produce a side-by-side view of LaTeX code and the corresponding output.

Here's what I have:

\documentclass{article}
\usepackage{listings,filecontents}

\begin{document}

\newenvironment{testenv}{%
  \csname filecontents*\endcsname{\jobname.tmp}}{%
  \csname endfilecontents*\endcsname
  \noindent
  \begin{minipage}{0.5\textwidth}%
    \input{\jobname.tmp}%
  \end{minipage}%
  \begin{minipage}{0.5\textwidth}%
    \lstinputlisting[basicstyle=\ttfamily]{\jobname.tmp}%
  \end{minipage}%
}%

\begin{testenv}
Some lines?
of text !!!
here.
\end{testenv}

\end{document}

Expected output:

Actual result:

ERROR: Missing number, treated as zero.

--- TeX said ---
<to be read again> 
                   \openin 
l.1 Some lines?

@ChristianHupfer I copied this part from somewhere, but I think it's because the body of a filecontents* environment is treated as verbatim text, and then normal rules don't apply. — Ernest A, Jul 21 '16 at 16:10

score 4 · Accepted Answer · 2016-07-21T16:31:11.427

I find \tcbverbatimwrite from tcolorbox very convenient. It has support for listings as well and can be configured in multiple ways:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[most]{tcolorbox}
\begin{document}



\newenvironment{testenv}{%
  \begingroup%
  \tcbverbatimwrite{\jobname.tmp}}%
{\endtcbverbatimwrite\endgroup%
  \noindent
  \begin{minipage}{0.5\textwidth}%
    \input{\jobname.tmp}%
  \end{minipage}%
  \begin{minipage}{0.5\textwidth}%
    \lstinputlisting[basicstyle=\ttfamily]{\jobname.tmp}%
  \end{minipage}%
}

\begin{testenv}
Some lines?
of text !!!
here.
\end{testenv}

\end{document}

Improved version

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[most]{tcolorbox}
\begin{document}



\newenvironment{testenv}{%
  \begingroup%
  \tcbverbatimwrite{\jobname.tmp}}%
{\endtcbverbatimwrite\endgroup%
  \noindent
  \begin{minipage}{0.5\textwidth}%
    \input{\jobname.tmp}%
  \end{minipage}%
  \begin{minipage}{0.5\textwidth}%
    \lstinputlisting[basicstyle=\ttfamily]{\jobname.tmp}%
  \end{minipage}%
}


\newenvironment{othertestenv}{%
  \begingroup%
  \tcbverbatimwrite{\jobname.tmp}}%
{\endtcbverbatimwrite\endgroup%
  \noindent
  \tcbinputlisting{colback=white!30!yellow,text side listing,listing options={basicstyle=\ttfamily},listing file=\jobname.tmp}%
}

\begin{testenv}
Some lines?
of text !!!
here.
\end{testenv}

\begin{othertestenv}
Some lines?
of text !!!
here.
\end{othertestenv}


\end{document}

score 3 · Answer 2 · answered Jul 21 '16 at 17:41

3

So with tcolorbox you only need

\usepackage[listings]{tcolorbox}

...

\newtcblisting{testenv}{%
  colback=white,text side listing,boxrule=0pt,opacityframe=0}

and that's it!

\begin{testenv}
Some lines?
of \emph{text} !!!
here.
\end{testenv}

produces

answered Jul 21 '16 at 17:41

Ernest A

2,773

Yes, that would be a simpler version then – Jul 21 '16 at 17:53

Using \input inside environment fails

2 Answers2