Adding contents for the end of the document in the preamble

Question

I create lots of LaTeX documents and put all my declarations into a header.tex that I use with \input{header.tex} at the beginning. However, I am migrated that into a header.sty and just use \usepackage{header} now.

Either way, my document always contains the same last lines that include a bibliography. I would like to move that into my header.sty as well. Is there some way to add end-of-document content into the preamble somehow?

The code that I have in mind is:

\IfFileExists{\bibliographyfile}{
    \printbibliography
}{}

The \bibliographyfile is defined in the preamble already.

Answer 1

I suppose, the request was something in the following manner, loading everything automatically in the header.sty file.

Please change the \DefaultBibliographyStyle at will.

\documentclass[12pt]{scrbook}
\usepackage{blindtext} % Not needed really


%%%% Content for `header.sty`
\newcommand*{\bibliographyfile}{biblio}%
\newcommand*{\DefaultBibliographyStyle}{alpha}%
\newcommand*{\DefaultBibFileExtension}{.bib}%

\AtEndDocument{%
\bibliographystyle{\DefaultBibliographyStyle}
\bibliography{\bibliographyfile}%
%
\IfFileExists{\bibliographyfile\DefaultBibFileExtension}{%
  \printbibliography%
}{}{}%
}%

%%%%%%%%%%% End stop copying it to the 'header.sty' file.


\begin{document}

\chapter{First}
\blindtext

\cite{Lam94} and \cite{GSM97} wrote fine books about \LaTeXe and other things.\par

\blindtext[5]

\end{document}