# Is there any command that allow to access to the three argument of another command?

Suppose I have a command like this: \command{<command>}{<content>}{<value>}. Is there any way to access to the other arguments by having one of them? e.g. something like this:

\getcontent{<value> or <command>}%----> output: <content>
\getcommand{<content> or <value>}%----> output: <command>
\getvalue{<content> or <command>}%----> output: <value>


I also have no Idea how to define \command{<command>}{<content>}{<value>}?

Perhaps the following is an option:

\documentclass{article}

% \command{<command>}{<content>}{<value>}
\newcommand{\command}[3]{%
\expandafter\def\csname #2@cmd\endcsname{#1}%
\expandafter\def\csname #3@cmd\endcsname{#1}%
\expandafter\def\csname #1@cnt\endcsname{#2}%
\expandafter\def\csname #3@cnt\endcsname{#2}%
\expandafter\def\csname #1@val\endcsname{#3}%
\expandafter\def\csname #2@val\endcsname{#3}%
}
\newcommand{\getcontent}[1]{%
\ifcsname #1@cnt\endcsname
\csname #1@cnt\endcsname
\else
No command/value associated with #1.
\fi
}
\newcommand{\getcommand}[1]{%
\ifcsname #1@cmd\endcsname
\csname #1@cmd\endcsname
\else
No content/value associated with #1.
\fi
}
\newcommand{\getvalue}[1]{%
\ifcsname #1@val\endcsname
\csname #1@val\endcsname
\else
No command/content associated with #1.
\fi
}

\begin{document}

\command{abc}{def}{ghi}

\getcommand{def} % abc
\getcommand{ghi} % abc

\getcontent{abc} % def
\getcontent{ghi} % def

\getvalue{abc} % ghi
\getvalue{def} % ghi

\getcommand{jkl}% No jkl found

\getcontent{jkl}% No jkl found

\getvalue{jkl}% No jkl found

\end{document}


You'll note that, for convenience, I've left <command> as a string, rather than a control sequence. Since there's no context for the use of <command>, this might not be an issue.