Need to 'rescale' a complex document (page size and fonts) to A5 from A4

Question

What I'm asking might not be within my capabilities, but I'm trying to change a document to print on 74 pages of A5 instead of 74 pages of A4. I have managed to change the papersize to A5 but it prints on 146 pages, as the fonts are still at the original size!

I haven't a clue how to 'scale' all the fonts by 0.5 (i.e. make every instance of every character 50% of its original size). I've found some clues that adding [scaled=0.5] to a font package is something of a solution, but it doesn't work with the document I'm trying to change. Changing the \documentclass from 10pt to 5pt doesn't do anything (and maybe it wouldn't - I am clueless)

The header is below, I hope it's OK to post it all.

I can follow simple instructions, but this is my first exposure to this world!

\documentclass[10pt,a5paper,twoside]{article}

\usepackage[latin1]{inputenc}
\usepackage[german,english]{babel}
\usepackage[textwidth=11.3cm,textheight=18.0cm,includehead]{geometry}
\usepackage{multicol}
\usepackage{ifthen}




\newboolean{germanorder}
\setboolean{germanorder}{false}

\newboolean{usepdflinks}
\setboolean{usepdflinks}{true}

\usepackage{fancyhdr}
\pagestyle{fancy}
\fancyhf{}
\fancyhead[RO,LE]{\textbf\thepage}
\fancyhead[RE]{\textbf{\nouppercase{\leftmark}}}
\fancyhead[LO]{\textbf{\nouppercase{\rightmark}}}
\renewcommand{\sectionmark}[1]{\markboth{test}{\thesection.\ #1}}

\fancypagestyle{plain}{
    \fancyhf{}
    \fancyfoot[R]{\textbf{\thepage}}
    \renewcommand{\headrulewidth}{0pt}
    \renewcommand{\footrulewidth}{0pt}
}

\ifthenelse{\boolean{usepdflinks}}
{\usepackage[pdftex,pdfborder={0 0 0}]{hyperref}}
{
    \newcommand{\hyperlink}[2]{#2}
    \newcommand{\hypertarget}[2]{#2}
}

\newcommand{\comment}[1]{}   % Remove comments
\newcommand{\explanation}[1]{}   % Remove comments
\newcommand{\cardtext}[2][]{#2}
\newcommand{\apx}[2][]{#2}
\newcommand{\ruling}[2][]{#2}
\newcommand{\notenglish}[1]{#1$^\dagger$}
\newcommand{\changed}[2][]{#2}
\newcommand{\MOOR}{\textsc{MOOR}}

\newcommand{\de}[1]{(\textsl{\foreignlanguage{german}{#1}})}
\newcommand{\numberref}[1]{\textbf{\small #1}}
\newcommand{\cardref}[3]{\hyperlink{#3}{#1 %
\ifthenelse{\boolean{germanorder}}{\de{#2}}{\numberref{#3}}}}

%\newcommand{\card}[5]{\hypertarget{#3}{}%
%\ifthenelse{\boolean{germanorder}}{%   German and other languages
%\noindent\textbf{\textsl{#2}}\hfill\numberref{#3}\nopagebreak

%\noindent\textbf{#1}\hfill{\tiny#4}}{% English
%\noindent\textbf{#1}\hfill{\tiny#4\hspace{0.5em}}\numberref{#3}}%
%\nopagebreak

%\noindent#5\vspace{0.3\baselineskip} }

\newcommand{\card}[5]{\hypertarget{#3}{}%
\noindent\parbox[b]{5.24cm}{\noindent\textbf{#1}\\[-1ex]{\tiny#4}}%
\hfill{\hfill\raisebox{4pt}{\textbf{\Large #3}}}%
\nopagebreak

\noindent#5\vspace{0.5\baselineskip} }

\newcommand{\action}[3]{\noindent\hypertarget{#2}{\textbf{#1}}\hfill%
\nopagebreak

\noindent#3\vspace{0.3\baselineskip}}

\newcommand{\actionref}[2]{\hyperlink{#2}{``#1''}}

\newlength{\guessheight}
\settoheight{\guessheight}{I}
\newlength{\guessdepth}
\settodepth{\guessdepth}{g}
\addtolength{\guessheight}{0.6\guessdepth}
\addtolength{\guessdepth}{0.2\guessdepth}
\newlength{\guesswidth}
\settowidth{\guesswidth}{I}

\newcommand{\ecp}[2][]{\makebox[2pt][l]{\rule{\fboxrule}{\guessheight}\rule[\guessheight]{\guesswidth}{\fboxrule}}#2\makebox[2pt][r]{\rule[-\guessdepth]{\guesswidth}{\fboxrule}\rule[-\guessdepth]{\fboxrule}{\guessheight}}}

\newcommand{\english}[1]{%
\ifthenelse{\boolean{germanorder}}{}{\item \textsl{#1}}
}

\newenvironment{explanationlist}{\small\begin{list}{$\Rightarrow$}{\setlength{\topsep}{0pt}\setlength{\itemsep}{0pt}}}{\end{list}}

\newcommand{\sectionline}{\begin{center}\rule{4cm}{0.2mm}\end{center}}

\addtolength{\columnsep}{1mm}


\begin{document}

Answer 1

Perhaps you could use the pdfpages package to do this. Create a new .tex file that contains the following:

\documentclass[a5paper]{article}
\usepackage{pdfpages}
\begin{document}
\includepdf[pages=-]{originalfile}
\end{document}

Where originalfile.pdf is your original A4 document. Compile this with pdflatex and you should get an A5 version of your original.

(In response to a comment:) Using the filecontents environment you could keep the above code in the same file as your main file, and with arara you could automate the compilation. Code example:

% arara: pdflatex
% arara: pdflatex: { files: [a5version.tex]}
% arara: clean: { files: [a5version.tex, a5version.aux,a5version.log]}

\documentclass[a4paper]{article}
\usepackage{kantlipsum} % for dummy text

% create the file for a5 version
\usepackage{filecontents}
\begin{filecontents}{a5version.tex}
\documentclass[a5paper]{article}
\usepackage{pdfpages}
\begin{document}
\includepdf[pages=-]{originalfile} % insert filename of main file here
\end{document}
\end{filecontents}

\begin{document}
\kant
\end{document}

Answer 2

An easier solution with pgfpages (part of the pgf package).

You just need to use the following setup and your document will be resized to A5 paper.

\pgfpagesuselayout{resize to}[a5paper]

MWE

\documentclass[a4paper]{article}

\usepackage{pgfpages}
\pgfpagesuselayout{resize to}[a5paper]

\usepackage{blindtext} % just for the example

\begin{document}

\blinddocument % just for the example

\end{document} 

Output (in A5 format)

Answer 3

Using Ghostscript

Here is a little script, which can rescale your PDF to any paper format. The script uses the first parameter as input of a .pdf-file, the second parameter is the desired paper format. It writes the output to a file with the same name and and appends the new paper format to the name.

Please keep in mind, that scaling only works as expected for DIN A� Formats, because these have a long edge/short edge ratio of √2, no matter what size.

Run with bash.

#!/bin/sh

# Usage: First argument is PDF file
#        Second argument is paper format (e.g. a4)

gs -q -dNOPAUSE -dBATCH \
    -sDEVICE=pdfwrite \
    -sPAPERSIZE=$3 \
    -dFIXEDMEDIA \
    -dPDFFitPage \
    -sOutputFile="${1%%.*}-$2.pdf" \
    "$1"
echo "Output written to ${1%%.*}-$2.pdf"
exit 0