How to properly display backticks in verbatim environment?

Question

I am preparing a beamer presentation where I need to display some markdown code involving backticks. Specifically, I want to show backticks in the verbatim environment. However, LaTeX renders them as open quotation marks.

How can I ensure backticks in the verbatim environment display as backticks?

Here's a minimal example:

\begin{verbatim}
Example: `2 + 2`
\end{verbatim}

An ideal solution would not require me to change the code itself.

Answer 1

You can also use the relative new package upquote, which is explicitly created for that task – together with the change for single quote marks, compare How to make a real apostrophe or single-quote in LaTeX.

\documentclass{article}
\usepackage{upquote}
\begin{document}
\begin{verbatim}
Example: `2 + 2`
\end{verbatim}
\end{document}

Without upquote:

With upquote:

Answer 2

It is possible to do this with a variation of the code found under a similar question here.

In your case, add the following to your preamble:

\makeatletter
\let\@sverbatim\@verbatim
\def\@verbatim{\@sverbatim \verbatimwithtick}
{\catcode``=13 \gdef\verbatimwithtick{\chardef`=18 }} 
\makeatother

In the verbatim environment this sets the definition of ` to correspond to the 18th character in the font table which is a back tick. Normally it corresponds to an opening quote.

Answer 3

With eTeX, @jpallen doesn't need auxiliary commands:

\documentclass{article}
\makeatletter
{\catcode`\`=13
\xdef\@verbatim{\unexpanded\expandafter{\@verbatim}\chardef\noexpand`=18 }
}
\makeatother

\begin{document}
\begin{verbatim}
Example: `2 + 2`
\end{verbatim}
\end{document}