How can I put every `verbatim` environment inside a `Shaded` environment by changing the preamble only?

Question

Unfortunately, I have a lot of TeX code which should look different that it does not, but I cannot modify its code body. However, I can modify the preamble and for example, I have learned that I can redefine \texttt to make every

\texttt{text}

into

\colorbox{shadecolor}{\texttt{text}}

by running

\let\oldtexttt\texttt
\renewcommand{\texttt}[1]{\colorbox{shadecolor}{\oldtexttt{#1}}}

in the preamble. That might not be perfect, but it works great. However, now I want to put every verbatim environment inside a Shaded environment. Obviously I cannot use \renewcommand for this again. Is there something else I can use to make every

\begin{verbatim}
text
\end{verbatim}

into

\begin{Shaded}
\begin{verbatim}
text
\end{verbatim}
\end{Shaded}

by changing the preamble only?

Screenshots:

What it looks like:

What it should look like:

MCVE:

\documentclass[12pt]{article}
\usepackage{xcolor}
\usepackage{framed}

\definecolor{shadecolor}{RGB}{200,200,0}
\newenvironment{Shaded}{\begin{snugshade}}{\end{snugshade}}

\begin{document}

\begin{verbatim}
text
\end{verbatim}

\end{document}

Answer 1

We can use fancyvrb package, using similar technique as https://tex.stackexchange.com/a/468250/4686

\documentclass{article}
\usepackage{fancyvrb}
\usepackage{framed}
\usepackage[dvipsnames]{color}
\definecolor{shadecolor}{named}{Goldenrod}

\renewenvironment{verbatim}{%
  \VerbatimEnvironment
  \begin{shaded}
  \begin{Verbatim}%
}{%
  \end{Verbatim}%
  \end{shaded}%
}

\begin{document}

\begin{verbatim}
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
\end{verbatim}
\end{document}

If your fancyvrb version is in the 3.x series but before 3.2 of 2019/01/08 you may need to use this preamble instead:

\PassOptionsToPackage{dvipsnames}{xcolor}
\usepackage{fancyvrb}% loads xcolor hence option clash hence the above
\usepackage{framed}
\definecolor{shadecolor}{named}{Goldenrod}

(or load xcolor with dvipsnames option before loading fancyvrb), because for these releases fancyvrb loaded xcolor.

Answer 2

With etoolbox it's quite easy. You can use the \BeforeBeginEnvironment and \AfterEndEnvironment hooks:

\documentclass[12pt]{article}
\usepackage{xcolor}
\usepackage{framed}
\usepackage{etoolbox}

\definecolor{shadecolor}{RGB}{200,200,0}
\newenvironment{Shaded}{\begin{snugshade}}{\end{snugshade}}

\BeforeBeginEnvironment{verbatim}{\begin{Shaded}}
\AfterEndEnvironment{verbatim}{\end{Shaded}}

\begin{document}

\begin{verbatim}
text
\end{verbatim}

\end{document}

or, if you can't add more packages (although, chances are etoolbox was already loaded by another package), you can copy the relevant parts of the code:

\documentclass[12pt]{article}
\usepackage{xcolor}
\usepackage{framed}

\definecolor{shadecolor}{RGB}{200,200,0}
\newenvironment{Shaded}{\begin{snugshade}}{\end{snugshade}}

\makeatletter
% Copied from latex.ltx
\def\begin#1{%
  \csname @beforebegin@#1@hook\endcsname% <<-- Added this
  \@ifundefined{#1}%
    {\def\reserved@a{\@latex@error{Environment #1 undefined}\@eha}}%
    {\def\reserved@a{\def\@currenvir{#1}%
     \edef\@currenvline{\on@line}%
     \csname #1\endcsname}}%
  \@ignorefalse
  \begingroup\@endpefalse\reserved@a}
\def\end#1{%
  \csname end#1\endcsname\@checkend{#1}%
  \expandafter\endgroup\if@endpe\@doendpe\fi
  \csname @afterend@#1@hook\endcsname% <<-- Added this
  \if@ignore\@ignorefalse\ignorespaces\fi}
% Copied from etoolbox.sty
\DeclareRobustCommand{\BeforeBeginEnvironment}[1]{%
  \expandafter\gappto\csname @beforebegin@#1@hook\endcsname}
\DeclareRobustCommand{\AfterEndEnvironment}[1]{%
  \expandafter\gappto\csname @afterend@#1@hook\endcsname}
\newcommand{\ifundef}[1]{%
  \ifdefined#1%
    \ifx#1\relax
      \expandafter\expandafter
      \expandafter\@firstoftwo
    \else
      \expandafter\expandafter
      \expandafter\@secondoftwo
    \fi
  \else
    \expandafter\@firstoftwo
  \fi}
\DeclareRobustCommand{\gappto}[2]{%
  \ifundef{#1}
    {\xdef#1{\unexpanded{#2}}}
    {\xdef#1{\unexpanded\expandafter{#1}\unexpanded{#2}}}}
\makeatother

\BeforeBeginEnvironment{verbatim}{\begin{Shaded}}
\AfterEndEnvironment{verbatim}{\end{Shaded}}

\begin{document}

\begin{verbatim}
text
\end{verbatim}

\end{document}

Answer 3

You can use fancyvrb and fvextra:

\documentclass{article}
\usepackage{fancyvrb,fvextra}

\definecolor{shadecolor}{RGB}{200,200,0}

\RecustomVerbatimEnvironment{verbatim}{Verbatim}
{highlightlines=1-10000,highlightcolor=shadecolor}

\begin{document}

\begin{verbatim}
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
la$ la$ la$ la$ la$ la$ la$ la$ la$ la$ la$
\end{verbatim}
\end{document}

As far as I can see, there is no way to specify that you want to highlight all lines, so I set 10000 as the last line, which should be sufficient.