Mini Shell

%% docutils.sty: macros for Docutils LaTeX output.
%%
%%   Copyright © 2020 Günter Milde
%%   Released under the terms of the `2-Clause BSD license`, in short:
%%
%%      Copying and distribution of this file, with or without modification,
%%      are permitted in any medium without royalty provided the copyright
%%      notice and this notice are preserved.
%%      This file is offered as-is, without any warranty.

% .. include:: README.md
%
% Implementation
% ==============
%
% ::

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{docutils}
  [2021/05/18 macros for Docutils LaTeX output]

% Helpers
% -------
%
% duclass::

% class handling for environments (block-level elements)
% \begin{DUclass}{spam} tries \DUCLASSspam and
% \end{DUclass}{spam} tries \endDUCLASSspam
\ifx\DUclass\undefined % poor man's "provideenvironment"
 \newenvironment{DUclass}[1]%
  {% "#1" does not work in end-part of environment.
   \def\DocutilsClassFunctionName{DUCLASS#1}
     \csname \DocutilsClassFunctionName \endcsname}%
  {\csname end\DocutilsClassFunctionName \endcsname}%
\fi

% providelength::

% Provide a length variable and set default, if it is new
\providecommand*{\DUprovidelength}[2]{
  \ifthenelse{\isundefined{#1}}{\newlength{#1}\setlength{#1}{#2}}{}
}


% Configuration defaults
% ----------------------
%
% See `Docutils LaTeX Writer`_ for details.
%
% abstract::

\providecommand*{\DUCLASSabstract}{
  \renewcommand{\DUtitle}[1]{\centerline{\textbf{##1}}}
}

% dedication::

% special topic for dedications
\providecommand*{\DUCLASSdedication}{%
  \renewenvironment{quote}{\begin{center}}{\end{center}}%
}

% TODO: add \em to set dedication text in italics?
%
% docinfo::

% width of docinfo table
\DUprovidelength{\DUdocinfowidth}{0.9\linewidth}

% error::

\providecommand*{\DUCLASSerror}{\color{red}}

% highlight_rules::

% basic code highlight:
\providecommand*\DUrolecomment[1]{\textcolor[rgb]{0.40,0.40,0.40}{#1}}
\providecommand*\DUroledeleted[1]{\textcolor[rgb]{0.40,0.40,0.40}{#1}}
\providecommand*\DUrolekeyword[1]{\textbf{#1}}
\providecommand*\DUrolestring[1]{\textit{#1}}

% Elements
% --------
%
% Definitions for unknown or to-be-configured Docutils elements.
%
% admonition::

% admonition environment (specially marked topic)
\ifx\DUadmonition\undefined % poor man's "provideenvironment"
 \newbox{\DUadmonitionbox}
 \newenvironment{DUadmonition}%
  {\begin{center}
     \begin{lrbox}{\DUadmonitionbox}
       \begin{minipage}{0.9\linewidth}
  }%
  {    \end{minipage}
     \end{lrbox}
     \fbox{\usebox{\DUadmonitionbox}}
   \end{center}
  }
\fi

% fieldlist::

% field list environment (for separate configuration of `field lists`)
\ifthenelse{\isundefined{\DUfieldlist}}{
  \newenvironment{DUfieldlist}%
    {\quote\description}
    {\enddescription\endquote}
}{}

% footnotes::

% numerical or symbol footnotes with hyperlinks and backlinks
\providecommand*{\DUfootnotemark}[3]{%
  \raisebox{1em}{\hypertarget{#1}{}}%
  \hyperlink{#2}{\textsuperscript{#3}}%
}
\providecommand{\DUfootnotetext}[4]{%
  \begingroup%
  \renewcommand{\thefootnote}{%
    \protect\raisebox{1em}{\protect\hypertarget{#1}{}}%
    \protect\hyperlink{#2}{#3}}%
  \footnotetext{#4}%
  \endgroup%
}

% inline::

% custom inline roles: \DUrole{#1}{#2} tries \DUrole#1{#2}
\providecommand*{\DUrole}[2]{%
  \ifcsname DUrole#1\endcsname%
    \csname DUrole#1\endcsname{#2}%
  \else%
    #2%
  \fi%
}

% legend::

% legend environment (in figures and formal tables)
\ifthenelse{\isundefined{\DUlegend}}{
  \newenvironment{DUlegend}{\small}{}
}{}

% lineblock::

% line block environment
\DUprovidelength{\DUlineblockindent}{2.5em}
\ifthenelse{\isundefined{\DUlineblock}}{
  \newenvironment{DUlineblock}[1]{%
    \list{}{\setlength{\partopsep}{\parskip}
            \addtolength{\partopsep}{\baselineskip}
            \setlength{\topsep}{0pt}
            \setlength{\itemsep}{0.15\baselineskip}
            \setlength{\parsep}{0pt}
            \setlength{\leftmargin}{#1}}
    \raggedright
  }
  {\endlist}
}{}

% optionlist::

% list of command line options
\providecommand*{\DUoptionlistlabel}[1]{\bfseries #1 \hfill}
\DUprovidelength{\DUoptionlistindent}{3cm}
\ifthenelse{\isundefined{\DUoptionlist}}{
  \newenvironment{DUoptionlist}{%
    \list{}{\setlength{\labelwidth}{\DUoptionlistindent}
            \setlength{\rightmargin}{1cm}
            \setlength{\leftmargin}{\rightmargin}
            \addtolength{\leftmargin}{\labelwidth}
            \addtolength{\leftmargin}{\labelsep}
            \renewcommand{\makelabel}{\DUoptionlistlabel}}
  }
  {\endlist}
}{}

% rubric::

% informal heading
\providecommand*{\DUrubric}[1]{\subsubsection*{\emph{#1}}}

% sidebar::

% text outside the main text flow
\providecommand{\DUsidebar}[1]{%
  \begin{center}
    \colorbox[gray]{0.80}{\parbox{0.9\linewidth}{#1}}
  \end{center}
}

% title::

% title for topics, admonitions, unsupported section levels, and sidebar
\providecommand*{\DUtitle}[1]{%
  \smallskip\noindent\textbf{#1}\smallskip}

% subtitle::

% subtitle (for sidebar)
\providecommand*{\DUsubtitle}[1]{\par\emph{#1}\smallskip}

% documentsubtitle::

% subtitle (in document title)
\providecommand*{\DUdocumentsubtitle}[1]{{\large #1}}

% titlereference::

% titlereference standard role
\providecommand*{\DUroletitlereference}[1]{\textsl{#1}}

% transition::

% transition (break / fancybreak / anonymous section)
\providecommand*{\DUtransition}{%
  \hspace*{\fill}\hrulefill\hspace*{\fill}
  \vskip 0.5\baselineskip
}