%%
%% The LaTeX Companion, 3ed
%%
%% Example 3-4-41 on page I-201 in "url --- Typesetting \acsp {url}, path names, and the like".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{147.0pt}

  \setlength\parindent{0pt}
  \AtBeginDocument{\small}

%StartShownPreambleCommands
\usepackage{url}
\renewcommand\UrlLeft{<url: }\renewcommand\UrlRight{>}
\DeclareUrlCommand\email{\urlstyle{rm}%
 \renewcommand\UrlLeft{mail:\ }\renewcommand\UrlRight{}}
%StopShownPreambleCommands

\begin{document}
\url{https://latex-project.org}            \par
\email{frank.mittelbach@latex-project.org} \par
\path{$HOME/figures} oops picks up the global definition!
\end{document}