How to define new cite command with specific citation format?

Question

The standard \cite{some_ref} command produce citation text like [1], but i'm looking for citation like [1*]. How can i define new cite command for such behavior?

Answer 1

Since you are using natbib, there's no need to define any new commands; you can achieve the desired effect using the \citetext and \citealp commands:

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{test,
author={Steve Somebody},
title= {The Title},
year={2011},
publisher={The publisher}
}
\end{filecontents}
\documentclass{article}
\usepackage[numbers]{natbib}

\begin{document}

\citetext{\citealp{test}*}

\bibliographystyle{plain}
\bibliography{\jobname}

\end{document}

Answer 2

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{test,
author={Steve Somebody},
titel= {The Title},
year={2011},
}
\end{filecontents}
\documentclass{article}
\makeatletter
\DeclareRobustCommand\mycite{%
  \@ifnextchar [{\@tempswatrue\@mycitex}{\@tempswafalse\@mycitex[]}}
\def\@mycitex[#1]#2{\leavevmode
  \let\@citea\@empty
  \@mycite{\@for\@citeb:=#2\do
    {\@citea\def\@citea{,\penalty\@m\ }%
     \edef\@citeb{\expandafter\@firstofone\@citeb\@empty}%
     \if@filesw\immediate\write\@auxout{\string\citation{\@citeb}}\fi
     \@ifundefined{b@\@citeb}{\hbox{\reset@font\bfseries ?}%
       \G@refundefinedtrue
       \@latex@warning
         {Citation `\@citeb' on page \thepage \space undefined}}%
       {\@cite@ofmt{\csname b@\@citeb\endcsname}}}}{#1}} 
\def\@mycite#1#2{[{#1*\if@tempswa , #2\fi}]}%
\makeatother
\begin{document}
\cite{test}\qquad \mycite{test} \qquad \mycite[p.~1]{test}
\bibliography{\jobname}
\bibliographystyle{plain}
\end{document}

Answer 3

with a second switch it is a bit shorter. Use \cite or cite*

\RequirePackage{filecontents}
\begin{filecontents}{\jobname.bib}
@book{test,
author={Steve Somebody},
titel= {The Title},
year={2011},
}
\end{filecontents}
\documentclass{article}
\makeatletter
\newif\if@tempswb
\DeclareRobustCommand\cite{%
  \@ifnextchar*{\@tempswbtrue\cite@i}{\@tempswbfalse\cite@i*}}
\def\cite@i*{\@ifnextchar[{\@tempswatrue\@citex}{\@tempswafalse\@citex[]}}
\def\@cite#1#2{[{#1\if@tempswb*\fi\if@tempswa , #2\fi}]}%
\makeatother
\begin{document}

\cite{test}\qquad \cite*{test} \qquad \cite*[p.~1]{test}

\bibliography{\jobname}
\bibliographystyle{plain}
\end{document}