$Ok 尝试最少的例子：这是 doofus.tex
\documentclass[english]{letter}
\usepackage[T1]{fontenc}
\usepackage{color}
\makeatletter
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% User specified LaTeX commands.
\usepackage[epub]{doofus}
\usepackage{color}
\usepackage{ifthen}
\makeatother
\begin{document}
This is a test document for the the doofus boolean example;
Which one appears when I type $\doofus$?
\end{document}
以下是带有布尔声明选项的样式文件：
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{doofus}%
[2014/01/01 v0.01a LaTeX doofus package]%\filedate\space\fileversion\space
\typeout{Package doofus, \csname [email protected]\endcsname%
^^ Copyright (C) 2014 ^^J}
\RequirePackage{calc}
\RequirePackage{xkeyval}[2006/11/18]
\usepackage{ifthen}
\newboolean{@epubstate}
\setboolean{@epubstate}{false}
\DeclareOption{epub}{\setboolean{@epubstate}{true}}
\ProcessOptions%
\ifthenelse{\boolean{epubstate}}{\newcommand{\doofus}{\textcolor{black}{7\spadesuit}}}{\newcommand{\doofus}{\textcolor{red}{7\heartsuit}}}
以下是日志输出摘录：
! Undefined control sequence. \@gtempa ...ue \ifnum \@ne =\@ne \fi
\ifepubstate
\relax \TE@setvaltrue \els... l.16 \ifthenelse{\boolean{epubstate}}
{\newcommand{\doofus}{\textcolor{black}...
? X