12 catcode for UNDERSCORE and character printed

Question

Does a LaTeX3 version of the following code could be simpler? I understand the logic, but I dislike the code...

\documentclass[12pt]{article}
\usepackage{color}
% Source: https://tex.stackexchange.com/a/33478/6880
\def\test{%
  \begingroup
  \catcode`_=12\relax
  \ttest}
\def\ttest#1{%
  \color{red}\fbox{#1}%
  \endgroup}
\begin{document}
The smallest \test{txt_example} in the world.
\end{document}

Another question. Is there a way to see an underscore because I have the following output?

In OT1 encoded fonts, the slot for _ is taken by the dot accent (unless you use \ttfamily). — egreg, Dec 03 '22 at 23:23

score 1 · Accepted Answer · answered Dec 03 '22 at 23:27

In OT1 encoded fonts, the slot for _ is taken by the dot accent, unless you use \ttfamily. Use T1.

Is there a simpler version? Yes, there is.

\documentclass[12pt]{article}
\usepackage{color}
\NewDocumentCommand{\test}{v}{%
  \fbox{\fontencoding{T1}\selectfont\textcolor{red}{#1}}%
}
\begin{document}
The smallest \test{txt_example} in the world.
\end{document}

The v argument specifier means “collect the argument verbatim”.

With \ttfamily instead of \fontencoding{T1}\selectfont you'd get

Of course you don't need to select the encoding if you have \usepackage[T1]{fontenc} in your document preamble, which is essentially mandatory for documents in (continental) European languages, including French.

Very instructive. I understand the TeX version, but definitely LaTeX3 wins here. Thanks for all. — projetmbc, Dec 03 '22 at 23:39

12 catcode for UNDERSCORE and character printed

1 Answers1