%% $Id: hvextern.tex 1320 2026-07-03 18:02:48Z herbert $
%\DocumentMetadata{}% for lualatex and pstricks
\documentclass[english,paper=a4,twoside,usegeometry]{scrartcl}
\usepackage{babel}
\usepackage{libertinus}
\usepackage[Scale=MatchLowercase,FakeStretch=0.88]{juliamono}% For the mono font
%\setmonofont[Scale=MatchLowercase,FakeStretch=0.88]{AnonymousPro}
\newfontfamily\NotoSansMono[Ligatures=TeX,Scale=MatchLowercase,
	FakeStretch=0.90,Ligatures=ResetAll%,RawFeature=-tlig
	]{Noto Sans Mono}
\newfontfamily\CodeTwo{CODE2000}[Scale=MatchLowercase]

\usepackage[includeheadfoot,bmargin=1cm,tmargin=5mm,textwidth=16cm]{geometry}

\usepackage{iftex}

\usepackage[automark]{scrlayer-scrpage}
\pagestyle{scrheadings}
\usepackage{hvlogos}
\usepackage[checkCode]{hvextern}
\usepackage{hvindex}
\usepackage{hvdoctools}
\usepackage{listings}
\lstset{basicstyle=\ttfamily\small,language=[LaTeX]TeX,breaklines}  
\usepackage{xcolor,xspace,varioref}
\usepackage{hyperref}

\def\Python{\textsf{Python}\xspace}
\def\Perl{\textsf{Perl}\xspace}
\def\Lua{\textsf{Lua}\xspace}
\def\Java{\textsf{Java}\xspace}

\AtBeginDocument{\MathCollectFalse\SuspendTagging}


\raggedbottom


\begin{document}
\title{Writing, running and including the output of external documents 
from within a main\newline \LaTeX\ document~--v. \hvexternFileversion}
\author{Herbert Voß \url{hvoss@tug.org}\thanks{Thanks to Karl Berry; Denis Bitouzé;
Werner Lemberg; Rolf Niepraschk}}
\maketitle
\tableofcontents

\newpage

\setkeys{hv}{moveToExampleDir,ExampleDir=Exa,showFilename,verbose,force=false}


%\clearpage

\section{Loading the package}

\begin{verbatim}
\usepackage[Option]{hvextern}
\end{verbatim}

There exists only one  option \Loption{checkCode} which is  valid
for all \TeX-compiler. In this case an already existing  external file will only be compiled, if the
external code changed. This doesn't depends on the setting of the option \Lkeyword{force}. 
\Loption{checkCode} can speed up the compilation time.

\section{Syntax}

\addtocontents{toc}{\protect\enlargethispage{2ex}}

\begin{sloppypar}
This package allows to write external \MP, \TeX, \ConTeXt, \LaTeX, \LuaTeX, \LuaLaTeX, \XeTeX, \XeLaTeX, 
\Index{Lua}, \Index{Perl}, \Index{Java}, \Index{Python}, \Index{Wolframscript}, and /or \Index{R}
source code, which will then be run via \Loption{shell-escape} to create a PDF or text output to include
it into the main \LaTeX\ document. The values for the
optional argument \Lkeyword{compiler}  must be the real prgram 
name  on the the local system, e.g. for Windows:
\Lprog{mpost}, \Lprog{tex}, \Lprog{context.exe}, \Lprog{latex.exe}, \Lprog{luatex.exe}, \Lprog{lualatex.exe}, \Lprog{xetex.exe}, \Lprog{xelatex.exe}, 
\Lprog{lua.exe}, \Lprog{perl.exe}, \Lprog{java.exe}, \Lprog{python.exe}, and/or \Lprog{Rscript.exe}.
\end{sloppypar}


There is only one environment and one command:

\begin{verbatim}
\begin{externalDocument}[<options>]{<external filename without extension>}
...
source code
...
\end{externalDocument}

\runExtCmd[<options>]
    {<command with arguments>}
    {<external filename without extension>}
\end{verbatim}

The very first compilation run of the main document must be done
  with the \Loption{-shell-escape} command-line option, otherwise it won't
  work.  Follow-up runs, for example, to resolve references, should
  usually be done without \Loption{-shell-escape}.
The currently used filename for the example is saved in the 
macro \Lcs{hvExternFilename}.

\begin{verbatim}
lualatex --shell-escape <file>
\end{verbatim}

The purpose for this package is to show the output of documents which have to be compiled with
a different preamble or a different engine or a complete different system, but integrating the output
automatically in the main document..

\bigskip
\noindent
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxsep-2\fboxrule\relax}
\emph{All} examples in this document are created on-the-fly while running this \LaTeX\ document
with \texttt{lualatex} with the  \texttt{-\kern1pt-shell-escape} option.
\end{minipage}}



\section{First examples}
\subsection{Without showing the code}

This document was run with \LuaLaTeX. Suppose you want to insert the output of a document
which needs for several reasons a \XeLaTeX\ run. Instead of created and running a document 
outside of the main document and then to insert the output
we can do this from within this \LuaLaTeX\ document itself. The external document is compiled
with \XeLaTeX\ and the output is insert as pdf image:
\begin{externalDocument}[%
  compiler=xelatex, inline, runs=2, grfOptions={height=8pt},%
  crop, cropmargin=0, cleanup, docType=latex,vshift=-1pt,verbose]{voss}
\documentclass{ctexart}
\pagestyle{empty}
\begin{document} 
美好的一天.
\end{document}
\end{externalDocument}



%
The current filename of the above example is \hvExternFilename\ and for the source 
see page \pageref{inline-exa}.

Let's show another example which needs a \pdfLaTeX\ run.  The \Index{source} code 
itself is also not
shown by the environment \Lenv{externalDocument}.


\begin{minipage}{.59\linewidth}
\begin{lstlisting}
\begin{externalDocument}[
  compiler=pdflatex,cleanup]{voss}
\documentclass{standalone}
%StartVisiblePreamble
\usepackage{fontenc}
\usepackage{libertinus}
\usepackage[linguistics]{forest}
\forestapplylibrarydefaults{linguistics, edges}
%StopVisiblePreamble
\begin{document}
\begin{forest}
[VP
  [DP]
  [V’
    [V]
  [DP]
  ]
]
\end{forest}
\end{document}
\end{externalDocument}
\end{lstlisting}
\end{minipage}
\begin{minipage}{.39\linewidth}
\begin{externalDocument}[
  compiler=pdflatex,cleanup={log,aux},showFilename=false]{voss}
\documentclass{standalone}
%StartVisiblePreamble
\usepackage{fontenc}
\usepackage{libertinus}
\usepackage[linguistics]{forest}
\forestapplylibrarydefaults{linguistics, edges}
%StopVisiblePreamble
\begin{document}
\begin{forest}
[VP
  [DP]
  [V’
   [V]
  [DP]
  ]
]
\end{forest}
\end{document}
\end{externalDocument}
\end{minipage}




\subsection{Showing code and output of a Python example}
The \ttIndex{png} image  is created on the fly with the following arguments of \Lenv{externalDocument}:

\begin{Verbatim}
\begin{externalDocument}[
  compiler=python3,
  showCode,
  ext=py,
  docType=py,
  usefancyvrb,
  grfOptions={width=\linewidth}]{python}
... Python code ...
\end{externalDocument}
\end{Verbatim}

The code which is declared as header and main can be marked by:

\begin{Verbatim}
\hv@extern@exampleType{py}
  {\NumChar StartVisibleMain}
  {\NumChar StopVisibleMain}
  {\NumChar StartVisiblePreamble}
  {\NumChar StopVisiblePreamble}
\end{Verbatim}

\Lcs{NumChar} is the default Python comment character \#\index{\#} and needs to be saved with a different
catagory, which is done internally by the package. The complete definition of the code is:


\begin{Verbatim}
\begin{externalDocument}[
  compiler=python3,
  showCode,
  ext=py,
  docType=py,
  usefancyvrb,
  grfOptions={width=\linewidth}]{python}
import os
#StartVisiblePreamble
from PIL import Image
import subprocess
# drawing area (xa < xb and ya < yb)
xa = -0.1716
xb = -0.1433
ya = 1.022
yb = 1.044
maxIt = 1024  # iterations
imgx = 1000   # image size
imgy = 750
image = Image.new("RGB", (imgx, imgy))
#StopVisiblePreamble

#StartVisibleMain
for y in range(imgy):
    cy = y * (yb - ya) / (imgy - 1)  + ya
    for x in range(imgx):
        cx = x * (xb - xa) / (imgx - 1) + xa
        c = complex(cx, cy)
        z = 0
        for i in range(maxIt):
            if abs(z) > 2.0: break 
            z = z * z + c 
        r = i % 4 * 6
        g = i % 8 * 32
        b = i % 16 * 16
        image.putpixel((x, y), b * 65536 + g * 256 + r)
#StopVisibleMain
# now get the filename created by the latex document
imageName = os.path.basename(os.path.splitext(__file__)[0])+".png" # get filename
image.save(imageName, "PNG")
\end{externalDocument}
\end{Verbatim}

And with using this code we get the image as png inserted. The given filename of the external
document is 
internally extended by a consecutive number which isn't known to the \Index{Python} code. However,
it is no problem in any programming language to get the name of a running file. The  forlast
line in the above code shows how it can be done with Python.

%\MathCollectFalse
%\SuspendTagging


\begin{externalDocument}[
  compiler=python3,
  progpath=/usr/local/bin/,
  runs=1,
  showCode,
  ext=py,
  docType=py,
  usefancyvrb,
  grfOptions={width=\linewidth}]{python}
import os
#StartVisiblePreamble
from PIL import Image
import subprocess
# drawing area (xa < xb and ya < yb)
xa = -0.1716
xb = -0.1433
ya = 1.022
yb = 1.044
maxIt = 1024  # iterations
imgx = 1000   # image size
imgy = 750
image = Image.new('RGB', (imgx, imgy))
#StopVisiblePreamble

#StartVisibleMain
for y in range(imgy):
    cy = y * (yb - ya) / (imgy - 1)  + ya
    for x in range(imgx):
        cx = x * (xb - xa) / (imgx - 1) + xa
        c = complex(cx, cy)
        z = 0
        for i in range(maxIt):
            if abs(z) > 2.0: break 
            z = z * z + c 
        r = i % 4 * 6
        g = i % 8 * 32
        b = i % 16 * 16
        image.putpixel((x, y), b * 65536 + g * 256 + r)
#StopVisibleMain
# now get the filename created by the latex document
imageName = os.path.basename(os.path.splitext(__file__)[0]) # get filename
image.save(imageName+'.png', 'PNG')
\end{externalDocument}

%\end{document}

The external filename, extended by a consequtive number, kan be printed in the
margin by setting the keyword \Lkeyword{showFilename}. In general it is printed 
in the outer margin or in twocolumn mode in the outer column. If the example is
set in twocolumn mode but inside a starred floating environment over both
column, then use the keyword \Lkeyword{outerFN}. Then \Lpack{hvextern} doesn't
test for twocolumn mode.

\enlargethispage{\normalbaselineskip}

A vertical shift of the filename is possible by setting a length to the keyword \Lkeyword{shiftFN},
e.g. \texttt{shiftFN=5ex}. 


%\clearpage%%%%%%%%%%%%

\begin{externalDocument}[grfOptions={width=0.95\linewidth},
  compiler=xelatex,showCode,mpwidth=0.6\linewidth,
  crop,cleanup,usefancyvrb=false,ext=tex,showFilename=false]{voss}
\documentclass{article}
%StartVisiblePreamble
\usepackage{tikz}
\usepackage[hks,pantone,xcolor]{xespotcolor}
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\SetPageColorSpace{HKS}
\definecolor{HYellow}{spotcolor}{HKS05N,0.5}
\definecolor{HRed}{spotcolor}{HKS14N,0.5}
\definecolor{HBlue}{spotcolor}{HKS38N,0.5}
\begin{tikzpicture}[scale=0.7,fill opacity=0.7]
 \fill[HYellow]( 90:1.2) circle (2);
 \fill[HRed]   (210:1.2) circle (2);
 \fill[HBlue]  (330:1.2) circle (2);
 \node at ( 90:2)  {Typography};
 \node at ( 210:2) {Design};
 \node at ( 330:2) {Coding};
 \node {\LaTeX};
\end{tikzpicture}
\end{document}
\end{externalDocument}



\section{Setting marker in the source}
The marker for the code ranges which should be listed depend to the used programming language:

\begin{verbatim}
[...]
%StartVisiblePreamble
[... listed preamble code ]
%StopVisiblePreamble
[...]
\begin{document}
[...]
\end{document}
\end{verbatim}

everything between \ttIndex{\%StartVisiblePreamble} and \ttIndex{\%StopVisiblePreamble} will be listed as
preamble and in case of a \LaTeX\ source everything between
 \Lcs{begin\{document\}} and \Lcs{end\{document\}} as body. The marker must be defined with an own
macro, e.g.:
 
\begin{verbatim}
\hv@extern@exampleType{py}
  {\NumChar StartVisibleMain}
  {\NumChar StopVisibleMain}
  {\NumChar StartVisiblePreamble}
  {\NumChar StopVisiblePreamble}
\end{verbatim}
 
\Lcs{NumChar} is the comment character \#, which needs a special handling. This version of \Lpack{hvextern}
supports the following programming languages (option \Lkeyword{compiler}):
\Lkeyval{mpost}, \Lkeyval{tex}, \Lkeyval{latex}, \Lkeyval{luatex}, 
\Lkeyval{python3}, \Lkeyval{perl}, \Lkeyval{lua}, \Lkeyval{xetex}, 
\Lkeyval{pdflatex}, \Lkeyval{lualatex}, \Lkeyval{xelatex}, and \Lkeyval{context}. The default
is \Lkeyval{pdflatex}. The option \Lkeyword{docType} selects the config file, which must be one of 
\Lkeyval{context}, \Lkeyval{lua}, \Lkeyval{pl}, \Lkeyval{tex}, \Lkeyval{latex}, 
\Lkeyval{mp}, and \Lkeyval{py}. For Lua it is

\begin{verbatim}
\hv@extern@exampleType{lua}
  {--StartVisibleMain}
  {--StopVisibleMain}
  {--StartVisiblePreamble}
  {--StopVisiblePreamble}
\end{verbatim}


It defines the marker strings for the listed code sequences.  
In some cases you have to use multiple times the same value
for different optional arguments, e.g.

\begin{verbatim}
ext=lua, compiler=lua, docType=lua, ... 
\end{verbatim}


\section{Optional arguments}
The default setting is always shown in brackets. 
\subsection{Programs and runs}

The \Lkeyword{progpath} should only in some
rare cases needed. In general all used compilers will be found by the system. A given \Lkeyword{progpath}
must be end with a slash, e.g. \Lkeyval{./bin/} 

\begin{verbatim}
\define@key{hv}{progpath}[]{\def\hv@extern@progpath{#1}}
\define@key{hv}{compiler}[pdflatex]{\def\hv@extern@compiler{#1}}
\define@key{hv}{runsequence}[]{\def\hv@extern@runsequence{#1}}
\define@key{hv}{runs}[1]{\setcounter{hv@extern@runs}{#1}}
\end{verbatim}

For Windows the \Lkeyword{progpath} should always be written with slashes and not
backslashes. e.g.

\begin{verbatim}
  compiler=Rscript.exe,
  progpath=C:/Program Files/R/R-4.3.3/bin/x64/,
\end{verbatim}

For macOS it is something like this:

\begin{externalDocument}[
  compiler=Rscript,
  progpath=/opt/homebrew/bin/,
  grfOptions={width=0.5\linewidth},
  showCode=true,
  usefancyvrb,
  ext=R,
  docType=R]{voss}
#StartVisibleMain
head(pressure) # Die ersten Werte der internen Datenliste
pdf()          # erzeugt die PDF "Rplots.pdf"
plot(pressure)
#StopVisibleMain
\end{externalDocument}


%\clearpage

Instead of the optional arguments
 \Lkeyword{compiler}, \Lkeyword{biber}, and \Lkeyword{xindex} one can define an individual
 command sequence by using the optional argument
 \Lkeyword{runsequence}. It must be comma separated list:
 
\begin{verbatim}
runsequence={lualatex,biber,xindex -l de -c AU,lualatex,lualatex}
\end{verbatim}

\begin{externalDocument}[
  grfOptions={width=0.30\linewidth},
  pages={1,3,5},
  pagesep=2pt,
  frame,
  runsequence={lualatex,biber,xindex -l de -c AU,lualatex,lualatex},
  verbose,
  cleanup={log,aux,toc,bbl,blg},
  showCode,docType=latex,
  lstOptions={columns=fixed}]{voss}
\documentclass[paper=a5,parskip=half-,DIV=12,fontsize=12pt]{scrbook}
%StartVisiblePreamble
\usepackage[ngerman]{babel}
\usepackage{libertinus,hvindex}
\usepackage{makeidx}\makeindex
\usepackage{biblatex}\addbibresource{biblatex-examples.bib}
%StopVisiblePreamble
\usepackage{blindtext}
\begin{document}
Sort with xindex \verb|-l DE --config AU|
\blindtext
\Index{Österreich} \Index{Öresund} 
\Index{Ostern} \Index{Ober} \Index{Oberin} 
\Index{Österreich} \Index{Öresund} 
\Index{Ödem} \Index{Oligarch} \Index{Oder} 
\Index{Goldmann}
\printindex
\nocite{*}\printbibliography
\blindtext
\blinddocument

\end{document}
\end{externalDocument}


The following \Java-program creates the Mandelbrot set as png image. The valid setting for 
the environment \Lenv{externalDocument} is:

\begin{verbatim}
  compiler=java,ext=java,docType=java,
\end{verbatim}

\begin{externalDocument}[
  verbose,
  compiler=java,ext=java,showCode,
  docType=java,includegraphic,
  usefancyvrb,grfOptions={width=0.9\linewidth}]{java}
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.awt.image.RenderedImage;
import java.io.File;
import javax.imageio.ImageIO;

public class Main {

//StartVisiblePreamble
  public static int iterZahl(final double cx, final double cy, int maxIt, 
                final double radius) {
  // bestimmt Anzahl der Iterationen
    int zaehler = 0;
    double zx = 0.0, zy = 0.0, tmp;
    do {
      tmp = zx*zx - zy*zy + cx;
      zy = 2*zx*zy + cy; zx = tmp;
      zaehler++;
    } while (zx*zx + zy*zy <= radius && zaehler < maxIt);
    return zaehler;
  }
//StopVisiblePreamble
  public static void main(String[] argv) throws Exception {  
    String f_name = new File ((Main.class.getProtectionDomain().getCodeSource().getLocation().toURI()).getPath()).getName();
    String basename = f_name.replaceAll("\\.[^.]*$", "");
    int imageBreite = 540, imageHoehe = 405;
    BufferedImage bufferedImage = new BufferedImage(imageBreite, imageHoehe, BufferedImage.TYPE_INT_RGB);
    Graphics g = bufferedImage.createGraphics();
//StartVisibleMain
    double xa = -2.5, xe = 0.7, ya = -1.2, ye = 1.2; // Ratio 20:15 
    double dx = (xe-xa)/(imageBreite-1), dy = (ye-ya)/(imageHoehe-1);
    double cx, cy; int R, G, B;
    double radius = 10.0;  int maxIt = 1024;
    cx = xa;
    for (int sp = 0; sp < imageBreite; sp++) {
      cy = ye; // von oben nach unten
      for (int ze = 0; ze < imageHoehe; ze++) {
        int zIter = iterZahl(cx, cy, maxIt, radius);
        if (zIter == maxIt) {
          g.setColor(Color.WHITE);
          g.drawLine(sp, ze, sp, ze);
        } else { 
          R = zIter % 4 * 6 ; G = zIter % 8 * 32; B = zIter % 16 * 16;
          g.setColor(new Color(R,G,B));
          g.drawLine(sp, ze, sp, ze);
        }
        cy = cy - dy;
      } // for ze
      cx = cx + dx;
    } // for sp
//StopVisibleMain
    g.dispose();
    RenderedImage rendImage = bufferedImage;

    File file = new File(basename+".png");
    ImageIO.write(rendImage, "png", file);
  }
}
\end{externalDocument}


%$


\clearpage

\subsection{Grafik options}
\begin{verbatim}
\define@key{hv}{grfOptions}[]{\def\hv@extern@grfOptions{#1}}
\end{verbatim}

The option is passed to \Lcs{includegraphics}, e.g. \verb|angle=90,width=\linewidth| for
the follwing example.

\begin{externalDocument}[grfOptions={angle=90,width=\linewidth},
  compiler=xelatex,showCode,mpwidth=0.6\linewidth,
  crop,cleanup]{voss}
\documentclass{article}
%StartVisiblePreamble
\usepackage{tikz}
\usepackage[hks,pantone,xcolor]{xespotcolor}
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\SetPageColorSpace{HKS}
\definecolor{HYellow}{spotcolor}{HKS05N,0.5}
\definecolor{HRed}{spotcolor}{HKS14N,0.5}
\definecolor{HBlue}{spotcolor}{HKS38N,0.5}
\begin{tikzpicture}[scale=0.7,fill opacity=0.7]
 \fill[HYellow]   ( 90:1.2) circle (2);
 \fill[HRed] (210:1.2) circle (2);
 \fill[HBlue]  (330:1.2) circle (2);
 \node at ( 90:2) {Typography};
 \node at ( 210:2) {Design};
 \node at ( 330:2) {Coding};
 \node {\LaTeX};
\end{tikzpicture}
\end{document}
\end{externalDocument}



%\newpage%%%%%%%%%%%


\subsection{Listings options}

\begin{verbatim}
\define@key{hv}{lstOptions}[]{\def\hv@extern@lstOptions{#1}}
\end{verbatim}

The option is passed either to \Lcs{lstinputlisting}, or, if \Lkeyword{usefancyvrb} is active, 
to \Lcs{VerbatimInput}. The following example uses 

\begin{verbatim}
  lstOptions={basicstyle=\sffamily\itshape\scriptsize},
\end{verbatim}



\begin{externalDocument}[
  grfOptions={width=\linewidth},
  lstOptions={basicstyle=\sffamily\itshape\scriptsize},
  compiler=lualatex,
  showCode,
  mpwidth=0.6\linewidth,
  crop,
  cleanup,
  docType=latex]{voss}
\DocumentMetadata{}
\documentclass{article}
%StartVisiblePreamble
\usepackage{pst-calendar} 
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\psscalebox{0.3}{%
  \psCalDodecaeder[Year=2022,style=april]%
}
\end{document}
\end{externalDocument}



\subsection{Background color}

There are different colors for the preamble and body listing: the backgrund and frame color.
\begin{verbatim}
\define@key{hv}{BGpreamble}[black12]{\def\hv@extern@BGpreamble{#1}}
\define@key{hv}{BGbody}[black8]{\def\hv@extern@BGbody{#1}}
\define@key{hv}{BOpreamble}[black12]{\def\hv@extern@BOpreamble{#1}}
\define@key{hv}{BObody}[black8]{\def\hv@extern@BObody{#1}}
\end{verbatim}

The options are passed to \Lpack{tcolorbox} and preset to \Lcolor{black"!12} and \Lcolor{black"!8}.
The color of the frame is set to the same values, hence not seen. The following example uses

\begin{verbatim}
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
\end{verbatim}

%\clearpage

\begin{externalDocument}[
  grfOptions={width=\linewidth},
  lstOptions={fontsize=\small,fontfamily=tt},
  compiler=lualatex,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  mpwidth=0.6\linewidth,
  crop,
  cleanup,
  usefancyvrb,
  docType=latex]{voss}
\DocumentMetadata{}
\documentclass{article}
%StartVisiblePreamble
\usepackage{pst-calendar} 
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\psscalebox{0.3}{%
  \psCalDodecaeder[Year=2022,style=may]%
}
\end{document}
\end{externalDocument}

\subsection{Type of the source code}

The current version of \Lpack{hvextern} supports code written as
\MP, \plainTeX, \LaTeX, \ConTeXt, and Python. Every type has its own keywords for the 
linerange which should be printed for the preamble and
the body. For example the \texttt{latex} config is:

\begin{verbatim}
\hv@extern@exampleType{latex}%                   for _all_LaTeX engines   
  {\string\begin\string{document\string}}%       
  {\string\end\string{document\string}}%         
  {\perCent StartVisiblePreamble}%               
  {\perCent StopVisiblePreamble}%                

% only for the sequence latex->dvips->ps2pdf
\def\hv@extern@runLATEX#1#2#3#4{% path compiler file extension  
  \ifhv@extern@verbose \typeout{>>>> running #1#2 #3#4}\fi
  \ShellEscape{#1#2\space #3#4}%
  \ifhv@extern@verbose \typeout{>>>> running #1dvips #3}\fi
  \ShellEscape{#1dvips\space #3.dvi}%
  \ifhv@extern@verbose \typeout{>>>> running ps2pdf #3.ps}\fi
  \ShellEscape{#1ps2pdf\space -dAutoRotatePages=/None\space -dALLOWPSTRANSPARENCY\space  #3.ps}%
}
\end{verbatim}

If a source needs more than running the defined compiler, it must be defined by a macro
\begin{verbatim}
\def\hv@extern@run<NAME>#1#2#3#4{% path compiler file extension
...}
\end{verbatim}

The type of the source code can be different to the compiler, e.g. source \Lkeyval{latex},
but compiler \Lkeyval{lualatex}.

\subsection{Output more than one page}
The pages which should be printed can be defined by


\begin{verbatim}
\define@key{hv}{pages}[1]{\def\hv@extern@pages{#1}}
\define@key{hv}{pagesep}[1em]{\hv@extern@pagesep=#1}
\define@boolkey{hv}[hv@extern@]{frame}[true]{}
\end{verbatim}

With \Lkeyword{frame} the pages can be framed (internally by \Lcs{fbox}).
It is leaved to the user to choose the correct image width for the pages.
The separation between the pages is defined by the length \Lkeyword{pagesep}.
The following example uses:

\begin{verbatim}
  pages={1,2,3},
  pagesep=2pt,
  grfOptions={width=0.3\linewidth},
  compiler=lualatex, runs=2,  % for the TOC
  frame,
\end{verbatim}

\begin{externalDocument}[
  pages={1,2,3},
  pagesep=2pt,
  shiftFN=5ex,
  grfOptions={width=0.3\linewidth},
%  lstOptions={fontsize=\small,fontfamily=tt},
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
%  mpwidth=0.6\linewidth,
%  crop,
  cleanup,
  frame,
%  usefancyvrb,
%  float,
%  caption={An example for Coxeter images},
%  label=img:cox,
  docType=latex]{voss}
\documentclass{article}
%StartVisiblePreamble
\usepackage[american]{babel}
\usepackage{libertinus} 
\usepackage{blindtext} 
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\title{A multipage example}
\author{Erasmus von Rotterdam}
\maketitle
\tableofcontents
\blinddocument
\end{document}
\end{externalDocument}




\subsection{Output as floating object with caption and label}

By default the images are not inserted as a float. This can be changed by
the keyword \Lkeyword{float}, a caption and a label are optional. The float type is always
\Lenv{figure}.

\begin{verbatim}
\define@boolkey{hv}[hv@extern@]{float}[true]{}
\define@key{hv}{floatsetting}[]{\def\hv@extern@floatsetting{#1}}
\define@key{hv}{caption}[]{\def\hv@extern@caption{#1}}
\define@key{hv}{label}[]{\def\hv@extern@label{#1}}
\end{verbatim}

The image Figure~\ref{img:cox} shows an example for a floating object, which uses the floatsetting \verb|!htb|,
which is the default. Using a caption and a label are optional.

\begin{externalDocument}[
  grfOptions={width=\linewidth},
  lstOptions={fontsize=\small,fontfamily=tt},
%  lstOptions={basicstyle=\small\ttfamily},
  compiler=lualatex,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
%  mpwidth=0.6\linewidth,
  crop,
  cleanup,
  usefancyvrb,
  float,
  floatsetting=!ht,
  caption={An example for Coxeter images},
  label=img:cox,
  docType=latex]{voss}
\DocumentMetadata{}
\documentclass{article}
%StartVisiblePreamble
\usepackage{pst-coxeterp} 
%StopVisiblePreamble
\pagestyle{empty}
\begin{document}
\begin{pspicture}(-1,-1)(1,1)\Simplex[dimension=2]\end{pspicture}
\begin{pspicture}(-1,-1)(1,1)\Simplex[dimension=3]\end{pspicture}
\begin{pspicture}(-1,-1)(1,1)\Simplex[dimension=5]\end{pspicture}
\begin{pspicture}(-1,-1)(1,1)\Simplex[dimension=7]\end{pspicture}
\end{document}
\end{externalDocument}



%\clearpage%%%%%%%%%%%%%%%%%


\subsection{Cropping the PDF}
Instead of using the \Index{documentclass} \Lclass{standalone}, which already crops the created PDF,
one can use the optional argument \Lkeyword{crop}.

\begin{verbatim}
\define@boolkey{hv}[hv@extern@]{crop}[true]{}
\define@key{hv}{cropmargin}[2]{\def\hv@extern@cropmargin{#1 }}% length in pt
\end{verbatim}


It is also possible to crop a document with more than one page. In this case the
beginning and end of the pages should be on the same height. Otherwise the pages
will have different heights after \Index{cropping} (see next image). 
The follwoing example was created with

\begin{verbatim}
  pages={1,2,3},
  pagesep=2pt,
  grfOptions={width=0.3\linewidth},
  compiler=lualatex, runs=2,  % for the TOC
  frame,
  crop, cropmargin=5,%    5pt margin
\end{verbatim}

\begin{externalDocument}[
  pages={1,2,3},
  pagesep=2pt,
  grfOptions={width=0.3\linewidth},
%  lstOptions={fontsize=\small,fontfamily=tt},
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
%  mpwidth=0.6\linewidth,
  crop, cropmargin=5,
  cleanup,
  frame,
%  usefancyvrb,
%  float,
%  caption={An example for Coxeter images},
%  label=img:cox,
  docType=latex]{voss}
\documentclass{article}
%StartVisiblePreamble
\usepackage[american]{babel}
\usepackage{libertinus} 
\usepackage{blindtext} 
\pagestyle{headings}
%StopVisiblePreamble
\begin{document}
\title{A multipage example}
\author{Erasmus von Rotterdam}
\maketitle
\tableofcontents
\Blinddocument
\end{document}
\end{externalDocument}


\subsection{Code and output side by side}
By default the code and the output is on top of each other. With setting the
width of a minipage with \Lkeyword{mpwidth} greater than 0\,pt  the output will be side by side.

\begin{verbatim}
\define@key{hv}{mpwidth}[0pt]{\setlength\hv@extern@mpwidth{#1}}
\define@key{hv}{mpvalign}[0pt]{\def\hv@extern@mpvalign{#1}}
\end{verbatim}

\Lkeyword{mpwidth} is  the width of the code. The rest of the line, minus 1em for the space between
the minipages, will be the possible
width for the output and will be calculated automatically. The two \Index{minipages} are
aligned by defaults to its top. This can be changed by setting \Lkeyword{mpvalign} to \Lkeyval{c} 
or \Lkeyval{b}.


%\clearpage

\subsection{Horizontal alignment of the output}

%\begin{verbatim}
%\define@key{hv}{align}[\centering]{\def\hv@extern@align{#1}}
%\end{verbatim}

%\textbf{the default}
%
\begin{verbatim}
  align=\centering,  % default
\end{verbatim}
%
\begin{externalDocument}[
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  showFilename=false,
  crop,
  cleanup,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.5\linewidth}{5mm}
\end{document}
\end{externalDocument}

%\textbf{Left aligned}

\begin{verbatim}
  align=\raggedright,
\end{verbatim}

\begin{externalDocument}[
  align=\raggedright,
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showFilename=false,
  showCode,
  crop,
  cleanup,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.5\linewidth}{5mm}
\end{document}
\end{externalDocument}

%\textbf{Right aligned}

\begin{verbatim}
  align=\raggedleft,
\end{verbatim}


\begin{externalDocument}[
  align=\raggedleft,
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  showFilename=false,
  crop,
  cleanup,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.5\linewidth}{5mm}
\end{document}
\end{externalDocument}



\clearpage


Now the same for side by side output.

%\textbf{the default -- side by side}
\begin{verbatim}
  align=\centering,  mpwidth=0.5\linewidth,   % default for side by side
\end{verbatim}

\begin{externalDocument}[
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  crop,
  showFilename=false,
  cleanup,
  mpwidth=0.5\linewidth,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.25\linewidth}{5mm}
\end{document}
\end{externalDocument}

%\textbf{Left aligned -- side by side}

\begin{verbatim}
  align=\raggedright,   mpwidth=0.5\linewidth,
\end{verbatim}

\begin{externalDocument}[
  align=\raggedright,
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  showFilename=false,
  crop,
  cleanup,
  mpwidth=0.5\linewidth,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.25\linewidth}{5mm}
\end{document}
\end{externalDocument}

%\textbf{Right aligned -- side by side}

\begin{verbatim}
  align=\raggedleft,  mpwidth=0.5\linewidth,
\end{verbatim}


\begin{externalDocument}[
  align=\raggedleft,
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  showFilename=false,
  crop,
  cleanup,
  mpwidth=0.5\linewidth,
  aboveskip=0pt,belowskip=0pt,
  docType=latex]{voss}
\documentclass{article}
\pagestyle{empty}
\begin{document}
\rule{0.25\linewidth}{5mm}
\end{document}
\end{externalDocument}




\subsection{Inline images}
By default code and image are own paragraphs. With the optional argument \Lkeyword{inline} the created
image can be part of the \Index{current line}. This may make sense, if you need characters which are
not part of your current font.

\begin{verbatim}
\define@boolkey{hv}[hv@extern@]{inline}[true]{%
    \hv@extern@codefalse
    \hv@extern@showFilenamefalse}
\end{verbatim}

With the setting \LKeyset{inline=true} the optional keyword \Lkeyword{showCode}  and \Lkeyword{showFilename}
is automatically set to false. The
next  Chinese characters \label{inline-exa}
\begin{externalDocument}[
  compiler=xelatex, inline, runs=2, grfOptions={height=8pt},
  crop, cropmargin=0, vshift=-1pt,usefancyvrb,
  cleanup, docType=latex]{voss}%
\documentclass{ctexart}
\pagestyle{empty}
\begin{document}
美好的一天
\end{document}
\end{externalDocument}
are inserted as \Index{inline image} without showing the code. The complete code looks like:


\let\myFont\CodeTwo

\begin{Verbatim}[fontfamily=myFont]
With \Lkeyset{inline} the optional argument \Lkeyword{showCode} is 
automatically set to false. The next  Chinese characters 
\begin{externalDocument}[vshift=-1pt,
  compiler=xelatex, inline, runs=2, grfOptions={height=8pt},
  crop, cropmargin=0, cleanup, docType=latex]{voss}
\documentclass{ctexart}
\pagestyle{empty}
\begin{document}
美好的一天
\end{document}
\end{externalDocument}
are inserted as inline image without showing the code. The complete 
code looks like:
\end{Verbatim}

With the keyword \Lkeyword{vshift} the inserted image can be moved in vertically direction.

\subsection{Input text instead of an image}
By default the created pdf which can be, of course, only text, will be inserted by \Lcs{includegraphics}.
If you have only text as output and don't want to create a pdf you can insert this kind of
output as verbatim text by setting \Lkeyset{includegraphic=false}. 

\begin{verbatim}
\define@boolkey{hv}[hv@extern@]{includegraphic}[true]{}
\end{verbatim}


The textfile must have the same main filename with the extension
\Lext{txt}. As already mentioned, in every programming language you can get the current
used filename from within the code itself. The following \Perl example which calculates the
\Index{Kaprekar} constants uses 

\begin{verbatim}
my $filename = $0;             # the current filename
$filename =~ s/\.pl//;         # without extension .pl
$filename = "${filename}.txt"; # for the output
\end{verbatim}

Only for some completeness: a Kaprekar constant is a number $A$ with $\max(A)-\min(A)=A$. 
$\max$ and $\min$ are the
sorted digits of the number $A$: $495=954-459$.


\begin{externalDocument}[
  compiler=perl, docType=pl, ext=pl, includegraphic=false,
  showCode, mpwidth=0.6\linewidth]{voss}
#!/usr/bin/perl
#
# Herbert Voss 2005-05-31
#
#StartVisiblePreamble
my $zahl = 1;
my $anfang = 1;
my $ende = 9;
#StopVisiblePreamble
my $filename = $0;             # the current filename
$filename =~ s/\.pl//;         # without extension .pl
$filename = "${filename}.txt"; # for the output
my $found = 0;
open(my $fh, '>', $filename);

#StartVisibleMain
print $fh "Finding Kaprekarconstants ...\n";
while ($zahl < 8) {
  print $fh "${zahl}-stellig: ";
  foreach ($anfang...$ende) { # for every row $_
    @Zeichen = split(//,$_);
    $Min = join("",sort(@Zeichen));
    $Max = reverse($Min);
    $Dif=$Max-$Min;
    if($_ eq $Dif) {
      $found = 1;
      print $fh $_,",  ";
    }
  }
  if (!$found) { print $fh "---\n"; }
  else         { print $fh "\n";    }
  $found = false;
  $zahl = $zahl+1;
  $anfang = $anfang*10;
  $ende = $ende*10;
}
#StopVisibleMain
close $fh;
\end{externalDocument}


%$
Another example with running \Lua to calculate and print the \Index{Pascal's triangle}. The internal filename
is available with

\begin{verbatim}
local filename = arg[0]
local shortFN = str:match("(.+)%..+")   -- delete extension
outFile = io.open(shortFN..".txt","w+") -- open external file
\end{verbatim}


\begin{externalDocument}[
  compiler=lua, docType=lua, ext=lua, includegraphic=false, 
  showCode, usefancyvrb=false,textOptions={basicstyle=\ttfamily\footnotesize},
  shiftFN=6ex]{voss}
#!/usr/bin/env lua
local filename = arg[0]
local shortFN = filename:match("(.+)%..+")
outFile = io.open(shortFN..".txt","w+")

--StartVisiblePreamble
function nextrow(t)
  local ret = {}
  t[0], t[#t+1] = 0, 0
  for i = 1, #t do ret[i] = t[i-1] + t[i] end
  return ret
end

function triangle(n)
  t = {1}
  for i = 1, n do
    m = (n - i)
    for j = 1,m do outFile:write("    ") end
    for k = 1,i do outFile:write(string.format("%8s",t[k])) end
    outFile:write("\n")
    t = nextrow(t)
  end
end
--StopVisiblePreamble

--StartVisibleMain
triangle(10)
--StopVisibleMain
outFile:close()
\end{externalDocument}


\subsection{Running additional external programs}

For a \LaTeX\ additional programs for \Index{bibliography}, \Index{index}, a.s.o. maybe needed.

\begin{verbatim}
\define@boolkey{hv}[hv@extern@]{biber}[true]{}
\define@boolkey{hv}[hv@extern@]{xindex}[true]{}
\define@key{hv}{xindexOptions}[]{\def\hv@extern@xindexOptions{#1}}
\define@key{hv}{runsequence}[]{\def\hv@extern@runsequence{#1}}
\end{verbatim}

The \Lkeyword{biber} run needs no additional options, but for \Lkeyword{xindex} it maybe useful.
The following examples uses

\begin{verbatim}
\begin{externalDocument}[
  compiler=lualatex, runs=2, pages=2,crop,
  xindex, xindexOptions={-l DE --config AU},
  mpwidth=0.6\linewidth, usefancyvrb=false,
  docType=latex,
  ...
]{voss}
\end{verbatim}

%\setmonofont{DejaVu Sans Mono}[Scale=MatchLowercase,FakeStretch=0.9]



\begin{externalDocument}[
  grfOptions={scale=0.75},
  compiler=lualatex, runs=2,
  BGpreamble=red!10, BOpreamble=red, 
  BGbody=blue!8, BObody=blue,
  showCode,
  pages=2,
  crop,
  cleanup,
  xindex,
  xindexOptions={-l DE --config AU},
  mpwidth=0.6\linewidth,
  usefancyvrb=false,
  docType=latex]{voss}
\documentclass[paper=a6,DIV=18,parskip=half-]{scrartcl}
\pagestyle{empty}
\usepackage{libertinus}
\usepackage{juliamono}
\usepackage[ngerman]{babel}
\usepackage{multicol}
\makeatletter
\def\theindex{%    only for demonstration
  \newpage
  \section*{\indexname}
  \begin{multicols}{2}
  \parskip\z@ \@plus .3\p@\relax \parindent\z@
  \let\item\@idxitem}
\def\endtheindex{\end{multicols}}
\makeatother
%StartVisiblePreamble
\usepackage{makeidx}\makeindex
\usepackage{hvindex}
%StopVisiblePreamble
\begin{document}
Sort with xindex \verb|-l DE --config AU|
\Index{Österreich} \Index{Öresund} 
\Index{Ostern} \Index{Ober} \Index{Oberin} 
\Index{Österreich} \Index{Öresund} 
\Index{Ödem} \Index{Oligarch} \Index{Oder} 
\Index{Ostern} \Index{Ober} \Index{Oberin} 
\Index{Obstler} \Index{Öl} \Index{ölen} 
\Index{Oder|seealso{Fluss}} \Index{Göbel}
\Index{oder} \index{Fluss!Oder}
\Index{Goethe} \Index{Göthe} \Index{Götz}
\Index{Goldmann}
\printindex
\end{document}
\end{externalDocument}


Instad of using the options \Lkeyword{compiler}, \Lkeyword{biber}, and \Lkeyword{xindex} 
one can also use only the optional argument \Lkeyword{runsequence} to define an individuell
sequence of commands, e.g.:
\begin{verbatim}
runsequence={lualatex,biber,{xindex -l de -c AU},lualatex,lualatex}
\end{verbatim}

\begin{externalDocument}[
  grfOptions={width=0.30\linewidth},
  pages={1,2,3,4,5,6},
  pagesep=2pt,
  frame,
  runsequence={lualatex,biber,xindex -l de -c AU,lualatex,lualatex},
  verbose,
  cleanup={log,aux,toc,bbl,blg},
  showCode,docType=latex,
  lstOptions={columns=fixed}]{voss}
\documentclass[paper=a5,parskip=half-,DIV=12,fontsize=12pt]{scrbook}
%StartVisiblePreamble
\usepackage[ngerman]{babel}
\usepackage{libertinus,hvindex}
\usepackage{makeidx}\makeindex
\usepackage{biblatex}\addbibresource{biblatex-examples.bib}
%StopVisiblePreamble
\usepackage{blindtext}
\begin{document}
\blindtext
\Index{Österreich} \Index{Öresund} 
\Index{Ostern} \Index{Ober} \Index{Oberin} 
\Index{Österreich} \Index{Öresund} 
\Index{Ödem} \Index{Oligarch} \Index{Oder} 
\Index{Goldmann}
\printindex
\nocite{*}\printbibliography
\blindtext
\blinddocument

\end{document}
\end{externalDocument}






\subsection{Using \texttt{listings}}
The default is using \Lcs{lstinputlisting} for the printed code sequences.

\begin{externalDocument}[
  grfOptions={width=0.45\linewidth},
  pages={1,3},
  frame,compiler=pdflatex,
%  crop,
  runs=2,showCode,docType=latex,
  frame,
  lstOptions={columns=fixed}]{voss}
%StartVisiblePreamble
\documentclass[chapterprefix=on,parskip=half-,DIV=12,fontsize=12pt]{scrbook}
\DeclareNewSectionCommand[
  style=section,
  level=4,
  beforeskip=-3.25ex plus -1ex minus -.2ex,
  afterskip=1.5ex plus .2ex,
  font=\normalsize,
  indent=0pt,
  counterwithin=subsubsection
]{subsubsubsection}
\RedeclareSectionCommand[
  level=5,
  toclevel=5,
  tocindent=13em,
  tocnumwidth=5.9em,
  counterwithin=subsubsubsection
]{paragraph}
\RedeclareSectionCommand[
  level=6,
  toclevel=6,
  tocindent=15em,
  tocnumwidth=6.8em
]{subparagraph}
\setcounter{secnumdepth}{\subsubsubsectionnumdepth}
\setcounter{tocdepth}{\subsubsubsectiontocdepth}
%StopVisiblePreamble
\usepackage[ngerman]{babel}
\usepackage{libertinus}
\usepackage{blindtext}
\begin{document}
\tableofcontents
\chapter{Einführung}
\section{Ein Abschnitt}
\subsection{Ein Unterabschnitt}
\subsubsection{Ein Unter-Unterabschnitt}
\subsubsubsection{Ein Unter-Unter-Unterabschnitt}
\paragraph{Der normale Paragraph}
\blindtext
\subparagraph{Der normale Unterparagraph}
\blindtext
\blinddocument
\end{document}
\end{externalDocument}



It also possible to use \Lcs{VerbatimInput} from package \Lpack{fancyvrb}. In general
it makes no difference using the optional argument \Lkeyword{usefancyvrb} or not.


\begin{externalDocument}[
  grfOptions={width=0.23\linewidth},
  pages={1,2,3,4},pagesep=1pt,
  frame,compiler=pdflatex,
  showFilename,
%  crop,
  runs=2,showCode,docType=latex,
  frame,framesep=0pt,usefancyvrb]{voss}
%StartVisiblePreamble
\documentclass[chapterprefix=on,parskip=half-,DIV=12,fontsize=12pt]{scrbook}
\DeclareNewSectionCommand[
  style=section,
  level=4,
  beforeskip=-3.25ex plus -1ex minus -.2ex,
  afterskip=1.5ex plus .2ex,
  font=\normalsize,
  indent=0pt,
  counterwithin=subsubsection
]{subsubsubsection}
\RedeclareSectionCommand[
  level=5,
  toclevel=5,
  tocindent=13em,
  tocnumwidth=5.9em,
  counterwithin=subsubsubsection
]{paragraph}
\RedeclareSectionCommand[
  level=6,
  toclevel=6,
  tocindent=15em,
  tocnumwidth=6.8em
]{subparagraph}
\setcounter{secnumdepth}{\subsubsubsectionnumdepth}
\setcounter{tocdepth}{\subsubsubsectiontocdepth}
%StopVisiblePreamble
\usepackage[ngerman]{babel}
\usepackage{libertinus}
\usepackage{blindtext}
\begin{document}
\tableofcontents
\chapter{Einführung}
\section{Ein Abschnitt}
\subsection{Ein Unterabschnitt}
\subsubsection{Ein Unter-Unterabschnitt}
\subsubsubsection{Ein Unter-Unter-Unterabschnitt}
\paragraph{Der normale Paragraph}
\blindtext
\subparagraph{Der normale Unterparagraph}
\blindtext
\blinddocument
\end{document}
\end{externalDocument}


%\clearpage


\subsection{Vertical space}

\begin{verbatim}
\define@key{hv}{aboveskip}[\medskipamount]{%
        \setlength\hv@extern@aboveskip{#1}}
\define@key{hv}{belowpreambleskip}[\smallskipamount]{%
        \setlength\hv@extern@belowpreambleskip{#1}}
\define@key{hv}{belowbodyskip}[\smallskipamount]{%
        \setlength\hv@extern@belowbodyskip{#1}}
\define@key{hv}{belowskip}[\medskipamount]{%
        \setlength\hv@extern@belowskip{#1}}
\end{verbatim}

\begin{description}
\item[\Lkeyword{aboveskip}] Vertical space \emph{before} the environment \Lenv{externalDocument} or
    the command \Lcs{runExtCmd} (default \Lcs{medskipamount})
\item[\Lkeyword{belowpreambleskip}] Vertical  space between preamble and body (default \Lcs{smallskipamount})
\item[\Lkeyword{belowbodyskip}] Vertical space between  body and output (default \Lcs{smallskipamount})
\item[\Lkeyword{belowskip}] Vertical space \emph{after}  the environment \Lenv{externalDocument} or
    the command \Lcs{runExtCmd} (default \Lcs{medskipamount})
\end{description}


The listings environment uses its own keywords \Lkeyword{aboveskip} and \Lkeyword{belowskip}, also preset
to \Lcs{medskipamount}. These ones can be changed by using the keyword \Lkeyword{lstOptions}:

\begin{verbatim}
..., lstOptions = {aboveskip=..., belowskip=...}, ...
\end{verbatim}




\subsection{No output}
By default there is an image or text as output of the external run. In a case, where
you are only interested in the code, which should be formatted in the same style as
other examples, you can set \Lkeyword{showOutput} to false.


\begin{externalDocument}[
  showOutput=false,
  frame,compiler=pdflatex,
  crop,
  runs=2,showCode,docType=latex,
  frame,usefancyvrb]{voss}
%StartVisiblePreamble
\documentclass[chapterprefix=on,parskip=half-,DIV=12,fontsize=12pt]{scrbook}
\DeclareNewSectionCommand[
  style=section,
  level=4,
  beforeskip=-3.25ex plus -1ex minus -.2ex,
  afterskip=1.5ex plus .2ex,
  font=\normalsize,
  indent=0pt,
  counterwithin=subsubsection
]{subsubsubsection}
%StopVisiblePreamble
\RedeclareSectionCommand[
  level=5,
  toclevel=5,
  tocindent=13em,
  tocnumwidth=5.9em,
  counterwithin=subsubsubsection
]{paragraph}
\RedeclareSectionCommand[
  level=6,
  toclevel=6,
  tocindent=15em,
  tocnumwidth=6.8em
]{subparagraph}
\setcounter{secnumdepth}{\subsubsubsectionnumdepth}
\setcounter{tocdepth}{\subsubsubsectiontocdepth}
\usepackage[ngerman]{babel}
\usepackage{libertinus}
\usepackage{blindtext}
\begin{document}
\tableofcontents
\chapter{Einführung}
\section{Ein Abschnitt}
\subsection{Ein Unterabschnitt}
\subsubsection{Ein Unter-Unterabschnitt}
\subsubsubsection{Ein Unter-Unter-Unterabschnitt}
\blindtext
\end{document}
\end{externalDocument}


%\clearpage%%%%%%%%%%%%%%

\section{Defining new marker}
Suppose you do not want for a \LaTeX\ document the complete body part between \Lcs{begin}
and \Lcs{end} printed. In this case you can define own markers, e.g.:

\begin{Verbatim}[fontsize=\small,label={New marker definition},fontfamily=tt]
\defMarkerType{ltx}
  {\perCent StartVisibleBody}
  {\perCent StopVisibleBody}     
  {\perCent StartVisiblePreamble}               
  {\perCent StopVisiblePreamble}
\end{Verbatim}

Whith this definition and the setting \Lkeyset{docType=ltx} the last example looks like:


\defMarkerType{ltx}
  {\perCent StartVisibleBody}
  {\perCent StopVisibleBody}     
  {\perCent StartVisiblePreamble}               
  {\perCent StopVisiblePreamble}


\begin{externalDocument}[
  grfOptions={width=\dimexpr\linewidth-2\fboxsep-2\fboxrule\relax},
%  pages={1},
  crop,
%  mpwidth=0.6\linewidth,
  frame,
  compiler=pdflatex,
  showFilename,
  runs=2,showCode,docType=ltx,
  usefancyvrb]{voss}
\documentclass[chapterprefix=on,parskip=half-,DIV=12,fontsize=12pt]{scrreprt}
%StartVisiblePreamble
\DeclareNewSectionCommand[
  style=section,
  level=4,
  beforeskip=-3.25ex plus -1ex minus -.2ex,
  afterskip=1.5ex plus .2ex,
  font=\normalsize,
  indent=0pt,
  counterwithin=subsubsection
]{subsubsubsection}
%StopVisiblePreamble
\RedeclareSectionCommand[
  level=5,
  toclevel=5,
  tocindent=13em,
  tocnumwidth=5.9em,
  counterwithin=subsubsubsection
]{paragraph}
\RedeclareSectionCommand[
  level=6,
  toclevel=6,
  tocindent=15em,
  tocnumwidth=6.8em
]{subparagraph}
\setcounter{secnumdepth}{\subsubsubsectionnumdepth}
\setcounter{tocdepth}{\subsubsubsectiontocdepth}
\usepackage[ngerman]{babel}
\usepackage{libertinus}
\usepackage{blindtext}
\makeatletter\let\ps@plain\ps@empty\makeatother
\begin{document}
\tableofcontents
\chapter{Einführung}
\section{Ein Abschnitt}
\subsection{Ein Unterabschnitt}
\subsubsection{Ein Unter-Unterabschnitt}
%StartVisibleBody
\subsubsubsection{Ein Unter-Unter-Unterabschnitt}
%StopVisibleBody
\blindtext
\end{document}
\end{externalDocument}




\section{Supported engines}
\subsection{\MP\ example}

Needs the run sequence setting to get a \texttt{pdf} from the created \texttt{dvi} output.
It is already internally defined. 

\begin{externalDocument}[
%  grfOptions={width=0.45\linewidth},
%  pages={1,3},
  frame,
  verbose=false,
  compiler=mpost,
  showFilename,
%  crop,
  cleanup,
  showCode,
  docType=mp,
  ext=mp,]{voss}
%StartVisiblePreamble
defaultfont:="ptmr8r";
warningcheck:=0;
%StopVisiblePreamble
beginfig(1)
draw fullcircle shifted (0.5,0.6) xscaled 8cm yscaled 3.5cm 
  withpen pencircle scaled 5bp withcolor red;
special( " /Times-Roman findfont 150 scalefont setfont " &
  " 0 10 moveto (MPost) false charpath clip stroke gsave 150 70 translate " &
  " 2 4 600 {dup 0 moveto 0 exch 0 exch 0 360 arc stroke} for grestore ");
endfig;
end;
\end{externalDocument}

For \MP\ exists an optional argument \Lkeyword{mposttex} which is preset
to \Lkeyval{tex}. If you want to run the \MP\ part with \LaTeX\ instead of
\TeX\ then use \texttt{mposttex=latex}.


\clearpage


\subsection{plain\TeX\ example}

Needs the run sequence setting to get a \texttt{pdf} from the created \texttt{dvi} output.
It is already internally defined. 


\begin{externalDocument}[
  grfOptions={width=0.5\linewidth},
%  pages={1,3},
  frame,
  verbose=false,
  compiler=tex,
  showFilename,
%  crop,
  showCode,
  docType=tex,
  ext=tex,]{voss}
\magnification=\magstep1
\baselineskip=12pt
\hsize=6.3truein
\vsize=8.7truein
\font\footsc=cmcsc10 at 8truept
\font\footbf=cmbx10 at 8truept
\font\footrm=cmr10 at 10truept
%StartVisiblePreamble
\footline={\footsc the electronic journal of combinatorics
   {\footbf 16} (2009), \#R00\hfil\footrm\folio}
%StopVisiblePreamble
%StartBody
\font\bigrm=cmr12 at 14pt
\centerline{\bigrm An elementary proof of the reconstruction conjecture}

\bigskip\bigskip
\centerline{D. Remifa\footnote*{Thanks to the editors of this journal!}}
\smallskip
\centerline{Department of Inconsequential Studies}
\centerline{Solatido College, North Kentucky, USA}
\centerline{\tt remifa@dis.solatido.edu}
\bigskip
\centerline{\footrm 
Submitted: Jan 1, 2009; Accepted: Jan 2, 2009; Published: Jan 3, 2009}
\centerline{\footrm Mathematics Subject Classifications: 05C88, 05C89}
\bigskip\bigskip
\centerline{\bf Abstract}
\smallskip
{\narrower\noindent
The reconstruction conjecture states that the multiset of unlabeled
vertex-deleted subgraphs of a graph determines the graph, provided it
has at least 3 vertices.  A version of the problem was first stated
by Stanis\l aw Ulam.  In this paper, we show that the conjecture can
be proved by elementary methods.  It is only necessary to integrate
the Lenkle potential of the Broglington manifold over the quantum
supervacillatory measure in order to reduce the set of possible
counterexamples to a small number (less than a trillion).  A simple
computer program that implements Pipletti's classification theorem
for torsion-free Aramaic groups with simplectic socles can then
finish the remaining cases.}

\bigskip
\beginsection 1. Introduction.

This is the start of the introduction.
\bye
\end{externalDocument}



\subsection{\LuaLaTeX\ example}
With Lua\LaTeX\ and and using PostScript code the intermediate GhostScript run is
not needed. The \texttt{pdf} is directly created.

\begin{externalDocument}[
  grfOptions={width=0.5\linewidth},
%  pages={1,3},
%  frame,
  verbose=false,
  compiler=lualatex,
  showFilename,
  crop,
  showCode,
  docType=latex,
  ext=tex,]{voss}
\documentclass{report}
\pagestyle{empty}
%StartVisiblePreamble
\usepackage{fontenc}\usepackage{libertinus}
\usepackage{pst-all}
%StopVisiblePreamble
\begin{document}
\psset{unit=0.8cm}
\begin{pspicture}(-9,-15)(9,2)
\psaxes(0,0)(-9,-15)(9,2)
\psplot[algebraic,plotstyle=curve,curvature=1 1 0, 
  linewidth=2pt,linecolor=red]{-8}{8}{
  1 - 3876218985722260225*x^2/10892114744073986176 
    + 14975974793271450625*x^4/174273835905183778816 
    - 317095420958296875*x^6/26811359370028273664 
    + 194412970920703125*x^8/214490874960226189312 
    - 2090988251953125*x^10/53622718740056547328 
    + 99480224609375*x^12/107245437480113094656 
    - 7879638671875*x^14/697095343620735115264 
    + 152587890625*x^16/2788381374482940461056}
\end{pspicture}
\end{document}
\end{externalDocument}


\subsection{\ConTeXt\ example}


\begin{externalDocument}[
  grfOptions={width=0.31\linewidth},
  pages={1,2,3,4,5,6},
  pagesep=2pt,
  frame,
  framesep=0pt,
  verbose=false,
  compiler=context,
  showFilename,
  runs=2,
  force,
  showCode,
  docType=context,
  ext=tex,]{voss}
%StartVisiblePreamble
\definehead
  [myhead]
  [section]
\setuphead
  [myhead]
  [numberstyle=bold,
   textstyle  =bold,
   before     =\hairline\blank,
   after      =\nowhitespace\hairline]
%StopVisiblePreamble
\starttext
\startstandardmakeup
\midaligned{From Hasselt to America}
\midaligned{by}
\midaligned{J. Jonker and C. van Marle}
\stopstandardmakeup
\placecombinedlist[content]
\chapter{Introduction}
\input knuth \input knuth 
\chapter[rensselaer]{The Rensselaer family}
\input knuth
\section{The first born}
\input knuth 
\section{The early years}
... in those days Hasselt was ...
\input knuth
\section{Living and workin in America}
\input knuth
\chapter[lansing]{The Lansing family}
... the Lansing family was also ...
\input knuth
\chapter[cuyler]{The Cuyler family}
... much later Tydeman Cuyler ...
\input knuth
\myhead[headlines]{And the end of all}
foo
\stoptext
\end{externalDocument}


\subsection{Wolframscript example}

If the \Lprog{wolframscript} creates an image then the name must be either \texttt{wolfr@m.png}
or \texttt{wolfr@m.pdf}. Otherwise it cannot be input by the environment
\Lenv{externalDocument}! The codecan be splitted into a preamble and main part, if you want
this be marked in the code. The markers for wls are:

\begin{verbatim}
\hv@extern@ExampleType{wls}
  {(*StartVisibleMain*)}
  {(*StopVisibleMain*)}
  {(*StartVisiblePreamble*)}
  {(*StopVisiblePreamble*)}
\end{verbatim}

It is left to the user to decide, what is the preamble code and what is the main code.

\begin{externalDocument}[
  compiler=wolframscript, docType=wls, ext=wls, includegraphic=true, crop,
  showCode, %mpwidth=0.5\linewidth,
  verbose,showFilename]{demo}
(*StartVisiblePreamble*)
r[t_] := {Cos[t], Sin[t], a*t}
uT[t_] := Simplify[r'[t]/Norm[r'[t]], t \[Element] Reals];
vN[t_] := Simplify[uT'[t]/Norm[uT'[t]], t \[Element] Reals];
vB[t_] := Simplify[Cross[r'[t], r''[t]]/Norm[Cross[r'[t], r''[t]]], t \[Element] Reals];
(*StopVisiblePreamble*)
(*StartVisibleMain*)
Simplify[Norm /@ {uT[t], vN[t], vB[t]}, t \[Element] Reals];
a = 0.5; (* between -1 and 1. Expand/Compress the helix *)
s = 1.24; (* between -Pi/Abs[a]    and     Pi/Abs[a], whjere you see the Frenet-Serret frame *)
helix=Show[ParametricPlot3D[{r[t]}, {t, -Pi/Abs[a], Pi/Abs[a]}, PlotStyle -> {Blue, Thick}], 
 Graphics3D[{{Thick, Darker@Red, Arrow[{r[s], r[s] + uT[s]}]}, {Thick, Darker@Green, Arrow[{r[s], r[s] + vB[s]}]}, {Thick, Darker@Cyan,Arrow[{r[s], r[s] + vN[s]}]}}], 
 PlotRange -> {{-2, 2}, {-2, 2}, {-Pi, Pi}}, ViewPoint -> {2, -4, 3}]
Print[Style[" Spacial representation of {Cos [t],Sin[t], a*t }", 12, Bold]]
Print[Style["Red vector.- Representa el vector Tangente", Darker@Red]]
Print[Style["Cyan vector.- Representa el vector Normal", Darker@Cyan]]
Print[Style["Green vector.- Representa el vector Binormal", Darker@Green]]
Print[Style["for Herbert Voss", Darker@Blue] ]
Export["wolfr@m.pdf",helix]
(*StopVisibleMain*)
\end{externalDocument}

\subsection{Include the textoutput as math code}

\begin{verbatim}
\runExtCmd[redirect]%
   {wolframscript -c "LaplaceTransform[t^4 Sin[t],t,s]" -format LaTeX}%
   {wolfram}

The current filename is: \texttt{\hvExternFilename.txt}

\[ \input{\hvExternFilename.txt} \]
\end{verbatim}

\runExtCmd[redirect,showOutput=false,showCode=false]%
  {wolframscript -c "LaplaceTransform[t^4 Sin[t],t,s]" -format LaTeX}{voss}

The current filename is: \texttt{\hvExternFilename.txt}

\[ \input{\hvExternFilename.txt} \]


\section{Running external commands}
Integrating the current directory of this document we can use the macro \Lcs{runExtCmd} with
the optional argument \Lkeyword{redirect}

\begin{verbatim}
\runExtCmd[redirect]{ls -la}{voss}
\end{verbatim}

to get the directory listed:

\medskip
\runExtCmd[redirect,verbose]{ls -la}{voss}


\begin{verbatim}
\runExtCmd[redirect,verbose,lstOptions={basicstyle=\ttfamily\small}]{du}{voss}% *nix
\end{verbatim}



\medskip
\runExtCmd[redirect,verbose,lstOptions={basicstyle=\ttfamily\small}]{du}{voss}


\section{Other options}

\begin{description}
\item[\Lkeyword{vshift}] A length for a vertical shift of the object, only valid for the inline mode.
See document source of example~\vpageref{inline-exa}.
%\item[\Lkeyword{outerFN}] Only valid for the twocolumn mode with onecolumn floats (environment \texttt{figure*}),
%    to get the filename on the right or left of the whole page.
%\item[\Lkeyword{shiftFN}] A length to move the printed filename up or down.
\item[\Lkeyset{force=false}] can speed up the comiling time for the document. If a created image/output
already exists, there is no need to create it with the next run again and again. \emph This option is not valid
if the package option \Loption{checkCode} exists.
\item[\Lkeyword{cleanup}] the auxiliary files of a \LaTeX-run are deleted, preset to \texttt{aux}, \texttt{log}.
   It must be a comma seperated list of the extensions of the main file, s.g. \texttt{cleanup=\{aux,log\}}.
\item[\Lkeyword{moveToExampleDir}] move all examples into a directory, must be set \emph{before} the
option \Lkeyword{ExampleDir}.
\item[\Lkeyword{ExampleDir}] name of a directory for the examples, must 
	first be created by the user himself.
\item[\Lkeyset{tcbox=false}] Can be used if there are some negative interactions between package \Lpack{listings}
   and package \Lpack{tcolorbox}.
\item[\Lkeyword{framesep}] Value for \Lcs{fbox} if keyword \texttt{frame} is used.
\item[\Lkeyword{mpsep}] Distance between code and output (default 1\,em).
\item[\Lkeyword{pagesep}] Distance between pages for multipage output (default 1\,em).
\item[\Lkeyword{verbose}] Print control messages into the terminal and logfile.
\item[\Lkeyword{png}] create an png from the pdf.
\item[\Lkeyword{eps}] create an eps from the pdf (historical).
\end{description}


\printindex


\end{document}


