LaTeX Forum

\documentclass[a4paper]{scrreprt}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[ngerman]{babel}
\usepackage[babel,german]{csquotes}
\usepackage{fix-cm}
\usepackage{rotating}
\usepackage{tikz}
\usepackage[detect-all]{siunitx} 
\usepackage{chngcntr}
\counterwithout{figure}{chapter} 
\counterwithout{table}{chapter}
\usepackage{multirow}
\usepackage{longtable}
\usepackage{booktabs}
\usepackage{graphicx}
\usepackage[
style=authoryear-icomp,
dashed=true, 
backend=bibtexu,
]{biblatex}
\addbibresource{Bibliography.bib}
\providecommand{\mycite}{\cite}
\usepackage{setspace}

%%LAYOUT SETTINGS
\documentclass[a4paper, BCOR5mm,12pt, headsepline, DIV=calc]{scrartcl}
\usepackage{setspace}
\usepackage[automark, autooneside]{scrpage2} 
\pagestyle{scrheadings} 
\clearscrheadfoot 
\ihead{\textnormal{\textbf{{\headmark}}}} 
\ohead{\pagemark}
\usepackage[a4paper]{geometry}
\geometry{left=3cm, right=2cm, top=3cm, bottom=4cm} %if you need special page settings
\usepackage{float}
\usepackage{caption}
%%LANGUAGE SETTINGS
%%
\usepackage[T1]{fontenc} %makes the input become european standard confirm
\usepackage[utf8]{inputenc} %let me input in utf8
\usepackage[english]{babel} %new german spelling
%
%%BIBLIOGRAPHY SETTINGS
%%
\usepackage[babel,english]{csquotes} %advanced spelling
\usepackage[style=authoryear-icomp, dashed=true, backend=bibtex]{biblatex} %get my citation style, bibtex instead of bibtexu %cause bibtexu instable backend
%\addbibresource{bibliography/Bibliography.bib}
\providecommand{\mycite}{\cite}
%
%%FONT SETTINGS
%%
\usepackage{fix-cm}
%
%%TABLE SETTINGS
%%
\usepackage{multirow}
\usepackage{longtable}
\usepackage{booktabs}
\captionsetup[table]{font=small}
\captionsetup[table]{labelfont=bf}
\renewcaptionname{english}{\tablename}{Tab.}
%
%%GRAPIC SETTINGS
%%
\usepackage{graphicx}
\captionsetup[figure]{font=small}
\captionsetup[figure]{labelfont=bf}
\renewcaptionname{english}{\figurename}{Fig.}
%
%%UNIT SETTINGS
%%
%\usepackage[detect-all]{siunitx} %atm not uses
%
%%NUMBERING SETTINGS
%%
%\usepackage{chngcntr}
%\counterwithout{figure}{chapter} 
%\counterwithout{table}{chapter}
%
%%SPECIAL COMMANDS
%%
\newcommand{\species}[1]{\textsl{#1}}
\newcommand{\statistics}[1]{\textup{#1}}
%
%%OTHER SETTINGS
%%
%some other settings
%
\begin{document}
\begin{longtable}{l l}
\caption{long caption, which starts at the center (i want it to start on the right and -if becoming longer- seems to have the width of the page. But I want this flush with the table width and break at the end of the tablewith!}
\label{tab: long tabel}
\endhead
1 iteam & 2 item \\
3 item & 4 item \\
\end{longtable}
\end{document}

\documentclass[a4paper, BCOR5mm,12pt, headsepline, DIV=calc]{scrartcl}
\usepackage{caption}
\usepackage[T1]{fontenc} 
\usepackage[utf8]{inputenc} 
\usepackage[english]{babel} 
\usepackage{longtable}
\usepackage{booktabs}
\captionsetup[table]{font=small}
\captionsetup[table]{labelfont=bf}
\renewcaptionname{english}{\tablename}{Tab.}

\makeatletter
\newcommand\LastLTentrywidth{1em}
\newlength\longtablewidth
\setlength{\longtablewidth}{1in}
\newcommand\getlongtablewidth{%
 \begingroup
  \ifcsname LT@\roman{LT@tables}\endcsname
  \global\longtablewidth=0pt
  \renewcommand\LT@entry[2]{\global\advance\longtablewidth by ##2\relax\gdef\LastLTentrywidth{##2}}%
  \@nameuse{LT@\roman{LT@tables}}%
  \fi
\endgroup}
\makeatother
\begin{document}
\begin{longtable}{l l}\noalign{\getlongtablewidth\global\LTcapwidth=\longtablewidth}
\caption{long caption, which starts at the center (i want it to start on the right and -if becoming longer- seems to have the width of the page. But I want this flush with the table width and break at the end of the tablewith!}
\label{tab: long tabel}
\endhead
1 iteam & 2 item \\
3 item & 4 item \\
\end{longtable}
\end{document}