%% 
%%  A DANTE-Edition example
%% 
%%  Beispiel 04-01-6 auf Seite 130.
%% 
%%  Copyright (C) 2010 H. Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 

%%Run also: >>  << 
% Show page(s) 1

\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{218.59192pt}

\usepackage[utf8]{inputenc}% eventuell anpassen
\setlength\parindent{0pt}
\setlength\textwidth{5cm}

\usepackage{longtable,calc}
\newsavebox\TBox

\begin{document}
\sbox\TBox{\begin{tabular}{|l|c|r|p{1.5cm}|}
Links & Zentriert & Rechts & Box
\end{tabular}}
Links \hfill Zentriert \hfill Rechts
\begin{longtable}{|l|c|r|p{1.5cm}|}\hline
Links & Zentriert & Rechts & Box\\\hline
l & c & r & p\{1.5cm\}\\\hline
\end{longtable}
\setlength\LTleft{\textwidth-\wd\TBox}
\raggedleft Rechtsbündig
\begin{longtable}{|l|c|r|p{1.5cm}|}\hline
Links & Zentriert & Rechts & Box\\\hline
l & c & r & p\{1.5cm\}\\\hline
\end{longtable}
\setlength\LTleft{0.5\textwidth-0.5\wd\TBox}
\centering Zentriert
\begin{longtable}{|l|c|r|p{1.5cm}|}\hline
Links & Zentriert & Rechts & Box\\\hline
l & c & r & p\{1.5cm\}\\\hline
\end{longtable}
\end{document}