\input produces errors, copy&paste not

Question

I'm working currently on a beamer-document and want to use LaTeX-code. Therefore I set up the listings-package in the following way:

\documentclass[12pt]{beamer}
\usepackage{listings}
\usepackage{xcolor}
\definecolor{keywordcolor}{HTML}{102D5D}
\definecolor{darkgreen}{rgb}{0,.6,0}
\definecolor{commentcolor}{HTML}{562B71}
\lstset{
    language=[LaTeX]TeX,
    texcsstyle=*\bf\color{keywordcolor},
    numbers=left,
    breaklines=true,
    keywordstyle=\color{darkgreen},
    commentstyle=\itshape\color{commentcolor},
    morekeywords={},
    otherkeywords={$, \{, \}, \[, \]},
    tabsize=2,
    frame=leftline,
    basicstyle=\footnotesize\ttfamily,
    backgroundcolor=\color{black!5}}

\begin{document}

\begin{frame}[fragile]

    \begin{lstlisting}
    \usepackage[Option]{Paket}
    \end{lstlisting}

\end{frame}

\end{document}

The tex-file otherkeywords contains {$, \{, \}, \[, \]}. If I use \input, I'll get a bunch of errors. If I use the content for itself, I'll get the right result. Am I doing something wrong?

The errors:

Improper alphabetic constant backgroundcolor=\color{black!5}}
Extra \else backgroundcolor=\color{black!5}}
Improper alphabetic constant backgroundcolor=\color{black!5}}
Improper alphabetic constant backgroundcolor=\color{black!5}}
Paragraph ended before \filehook@@ensureext was complete
Missing \endcsname inserted

I tried all the suggestions at another question, but no success for me.

Sincerely

Tell as what type of errors those are. Also an MWE would be nice, that reproduces those errors. — polemon, Jun 01 '14 at 21:36
otherkeywords wants a list of (possibly escaped) characters, not the instructions to produce a list of characters. — egreg, Jun 01 '14 at 22:08

score 3 · Accepted Answer · answered Jun 01 '14 at 22:21

If the file otherkeywords.tex contains the value of key otherkeywords, then the value can given as macro in this case. Package catchfile helps in storing the contents of a file in a macro:

\usepackage{catchfile}
\CatchFileDef{\otherkeywords}{otherkeywords}{\endlinechar=-1\relax}
\lstset{
    % ...,
    otherkeywords=\otherkeywords,
    % ...,
}

\input can not be used here, because it is not expandable and it should produce the list with one expansion step. But \input can be used with \lstset:

% otherkeywords-alternative.tex
\lstset{otherkeywords={$, \{, \}, \[, \]}}

and in the main file:

\lstset{%
  % old entries without otherkeywords
}
\input{otherkeywords-alternative}

score 2 · Answer 2 · answered Jun 01 '14 at 22:31

A variation of Heiko's answer, with a new key:

\documentclass[12pt]{beamer}
\usepackage{listings}
\usepackage{xcolor}
\usepackage{catchfile}
\definecolor{keywordcolor}{HTML}{102D5D}
\definecolor{darkgreen}{rgb}{0,.6,0}
\definecolor{commentcolor}{HTML}{562B71}

\makeatletter
\lst@Key{otherkeywordsfile}{}{%
  \let\lst@otherkeywords\@empty
  \let\lst@temp\@empty
  \if\relax\detokenize{#1}\relax\else
    \CatchFileDef{\lst@temp}{#1}{\endlinechar=\m@ne}%
  \fi
  \expandafter\lst@for\expandafter{\lst@temp}\do{%
    \lst@MakeActive{##1}%
    \lst@lExtend\lst@otherkeywords{%
      \expandafter\lst@CArg\lst@temp\relax\lst@CDef
        {}\lst@PrintOtherKeyword\@empty}%
  }%
}
\makeatother

\lstset{
    language=[LaTeX]TeX,
    texcsstyle=*\bfseries\color{keywordcolor},
    numbers=left,
    breaklines=true,
    keywordstyle=\color{darkgreen},
    commentstyle=\itshape\color{commentcolor},
    morekeywords={},
%    otherkeywords={$, \{, \}, \[, \]},
    otherkeywordsfile=otherkeywords, % <---- the value is the file name
    tabsize=2,
    frame=leftline,
    basicstyle=\footnotesize\ttfamily,
    backgroundcolor=\color{black!5}}

\begin{document}

\begin{frame}[fragile]

    \begin{lstlisting}
    \usepackage[Option]{Paket}
    \end{lstlisting}

\end{frame}

\end{document}

In the otherkeywords.tex file the braces can be omitted, so it can be

$, \{, \}, \[, \]

A similar idea could be used for morekeywords.

\input produces errors, copy&paste not

2 Answers2