How to wrap LaTex command in new environment - latex

Question

This question has already been answered once (wrap LaTeX command in environment), yet I still struggle to make my own rather simple new environment command work.
What I wanted to do is to convert the following LaTex block, which shows the output of some code, into a command I can reuse.
\fbox{\begin{minipage}{\textwidth}
\texttt{
>> CODE OUTPUT
\end{minipage}}
It is clear that in order to make a new environment command that replicates what I do above, I will have to make use of wrappers. (Because of the \fbox and the \texttt command.)
I would like to do this without having to download yet another package, or going into the secret realms of LaTex with some predefined \dir command that is only there to do the same job twice.
Checking the link from before, it seems that a productive solution is to use \bgroup and \egroup. I would therefore write something like this:
\newenvironment{CodeOutput}
{\fbox\bgroup\begin{minipage}{\textwidth}\texttt\bgroup}
{\egroup\end{minipage}\egroup}
Yet this will still not work. (On Overleaf at least.) It would be great if there was a straightforward way of making commands like these. Thanks for any useful suggestions!

Answer 1

If want to write a command that does what you're after, then the following would work:
\newcommand{\mycmd}[1]{%
\fbox{%
\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\ttfamily #1
\end{minipage}%
}%
}
The idea here works because the <arg>ument supplied to \mycmd{<arg>} is replaced by #1 in its entirety. If you want want to rewrite this as an environment, it's a little more difficult, purely because of \fbox. \fbox is doesn't have an environment-form equivalent the same way \texttt has \ttfamily (which is technically a font switch). There is a quick way around it provided by environ - it allows you to capture the contents of an environment in a macro \BODY:
\usepackage{environ}
\NewEnviron{myenvA}{%
\fbox{%
\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\ttfamily \BODY
\end{minipage}%
}%
}
However, you do have the option by capturing the content of an environment inside a box and then setting the box inside an \fbox:
\newsavebox{\codebox}% To store the content of myenvB
\newenvironment{myenvB}{%
\begin{lrbox}{\codebox}%
\ttfamily\ignorespaces
}{%
\end{lrbox}%
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\usebox{\codebox}%
\end{minipage}}%
}
The following minimal example shows all the above cases:
\documentclass{article}
\usepackage{environ}
\newcommand{\mycmd}[1]{%
\fbox{%
\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\ttfamily #1
\end{minipage}%
}%
}
\NewEnviron{myenvA}{%
\fbox{%
\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\ttfamily \BODY
\end{minipage}%
}%
}
\newsavebox{\codebox}
\newenvironment{myenvB}{%
\begin{lrbox}{\codebox}%
\ttfamily\ignorespaces
}{%
\end{lrbox}%
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\usebox{\codebox}%
\end{minipage}}%
}
\begin{document}
\noindent
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\ttfamily SoMe CoDe HeRe
\end{minipage}}
\bigskip
\noindent
\mycmd{SoMe CoDe HeRe}
\bigskip
\noindent
\begin{myenvA}
SoMe CoDe HeRe
\end{myenvA}
\bigskip
\begin{lrbox}{\codebox}
\ttfamily SoMe CoDe HeRe
\end{lrbox}
\noindent
\fbox{\begin{minipage}{\dimexpr\linewidth-2\fboxrule-2\fboxsep}
\usebox{\codebox}
\end{minipage}}
\bigskip
\noindent
\begin{myenvB}
SoMe CoDe HeRe
\end{myenvB}
\end{document}