\begin{filecontents}{myheadings.sty}
\newcommand{\ps@normalheadings}
{
    \renewcommand{\@oddhead}
        {\footnotesize[{\ttfamily\mfilename}]\hfill\thepage}
    \renewcommand{\@evenhead}{\@oddhead}
    \renewcommand{\@oddfoot}{}
    \renewcommand{\@evenfoot}{\@oddfoot}
}
\newcommand{\ps@firstpageheadings}
{
    \renewcommand{\@oddhead}
    {
        \footnotesize
        \underline{\matlabversion}\hfill\underline{\irisversion}
    }
    \renewcommand{\@evenhead}{\@oddhead}
    \renewcommand{\@oddfoot}{}
    \renewcommand{\@evenfoot}{\@oddfoot}
}
\end{filecontents}

\begin{filecontents}{myitemize.sty}
\def\@listi{\leftmargin\leftmargini
    \parsep 0.2\baselineskip
    \topsep \parsep
    \itemsep 0.2\baselineskip
    \partopsep \z@}
\def\@listii{\leftmargin\leftmarginii
    \labelwidth\leftmarginii
    \advance\labelwidth-\labelsep
    \parsep 0.1\baselineskip
    \topsep 0.1\baelinesep
    \itemsep\parskip}            
\end{filecontents}

\documentclass[$papersize$,fleqn]{slides}
            
\usepackage[T1]{fontenc}
\usepackage[$papersize$,landscape,scale=$textscale$,pdftex]{geometry}
\usepackage{amsmath,color,graphicx,listings}
\usepackage{myheadings,myitemize}

$packages$

\definecolor{outputcodecolor}{rgb}{0,0,0.68}
\definecolor{inputcodebgcolor}{rgb}{0.8,0.8,0.8}
\definecolor{outputcodebgcolor}{rgb}{0.94,0.94,1}

\newcommand{\codesizeintitle}{\Large}
\newcommand{\codesizeintext}{\normalsize}
\newcommand{\codesize}{}

\newenvironment{myabstract}
{\pagebreak\begin{cell}{Introduction}}
{\end{cell}\pagebreak}

\lstdefinestyle{inputcode}{
   breaklines=false,
   language={},
   backgroundcolor=\color{inputcodebgcolor},
   columns=flexible,
   keepspaces=true,
   frame=single,rulecolor=\color{inputcodebgcolor},framerule=0.1em,
   numbers=left,
   numberstyle={\ttfamily},
   basicstyle={\color{black}\ttfamily\codesize},
   escapechar=",
   linewidth=500em,
}

\lstdefinestyle{outputcode}{
   breaklines=false,
   language={},
   backgroundcolor=\color{outputcodebgcolor},
   columns=flexible,
   keepspaces=true,
   frame=single,rulecolor=\color{outputcodebgcolor},framerule=0.1em,
   numbers=none,columns=flexible,
   basicstyle={\color{outputcodecolor}\ttfamily\codesize},
   escapechar={},
   linewidth=500em, %%%
}

\newcommand{\filetitle}{}
\newcommand{\mfilename}{}
\newcommand{\matlabversion}{$matlabversion$}
\newcommand{\irisversion}{$irisversion$}
\newcommand{\mfilenametitle}[1]{\smallskip\par {\normalsize[{\ttfamily #1}]}}

%%%% Cell environment %%%%%
\newenvironment{cell}[1]{
    {\centering\bfseries\color{blue}{#1}\bigskip\par}}
{}

%%%% Split cell environment %%%%%
\newenvironment{splitcell}{}{}

%%%%% Intro text environment %%%%%
\newenvironment{introtext}{}{\pagebreak}

%%%%% Input code environment %%%%%
\newenvironment{inputcode}
{\medskip\lstset{style=inputcode}}
{\pagebreak}

%%%%% Ouput code environment %%%%%
\newenvironment{outputcode}
{\medskip\lstset{style=outputcode}}
{\pagebreak}

%%%%% Bookmarks %%%%%
\newcommand{\circled}[1]
    {{\large\textcircled{\footnotesize\sffamily\raisebox{0.2pt}{#1}}}}
\newcommand{\bookmark}[1]
    {\textcolor{red}{\circled{#1}}}

%%%%% Title page %%%%%
\newcommand{\byauthor}
    {by \\[3pt]}
\renewcommand{\and}
    {\\[2pt] }
    
%%%%% Introduction %%%%%
\newcommand{\introduction}[2]
{
    \pagestyle{firstpageheadings}
    \title{\sffamily#1#2}
    \author{$author$}
    \date{\medskip $date$}
    \renewcommand{\codesize}{\codesizeintitle}
    \maketitle    
    \renewcommand{\codesize}{\codesizeintext}
    \pagebreak
    \pagestyle{normalheadings}
}

\renewcommand{\today}{\number\day\space\ifcase\month\or
    January\or February\or March\or April\or May\or June\or
    July\or August\or September\or October\or November\or December\fi
    \space\number\year}

\linespread{$linespread$}

$preamble$

\begin{document}

\renewcommand{\codesize}{\codesizeintext}

$body$

\end{document}