找出哪个包启用了给定的环境或命令

Question

我想出了这个宏\findpackagebycommand：

\makeatletter
% patched command of loading a package
\def\find@load#1[#2]#3[#4]{%
    % load the package
    \find@fileswith@pti@ns{#1}[#2]{#3}[#4]%
    % check if commands exists now
    \ifcsname\find@command\endcsname
        \typeout{Package #3 introduces command \find@command.}%
        % command has been found, revert to original version without checks
        \let\@fileswith@pti@ns\find@fileswith@pti@ns
    \else
        % somehow, \@fileswith@pti@ns is restored after loading a package
        % thus, patch it again
        \let\@fileswith@pti@ns\find@load
    \fi
}%

\newcommand*{\findpackagebycommand}[1]{%
    % using this multiple times - esp. when the package has not been found yet -
    % will break things. Thus, check first that \find@command has never been defined before
    \ifx\find@command\undefined
        \def\find@command{#1}%
        % first, check if this command is already defined
        \ifcsname\find@command\endcsname
            % in this case, just issue a warning and do nothing
            \@latex@warning@no@line{Command \find@command \space is already defined}%
        \else
            % overwrite the internal \@fileswith@pti@ns command, which does the actual loading
            % \@fileswith@pti@ns is used internally by \usepackage and \RequirePackage
            \let\find@fileswith@pti@ns\@fileswith@pti@ns
            \let\@fileswith@pti@ns\find@load
        \fi
    \else
        % used multiple times - prevent and give a warning
        \@latex@warning@no@line{You can use \protect\findpackagebycommand \space only once}%
        \errmessage{Invalid use of command findpackagebycommand.}%
    \fi
}

\makeatother

\usepackage如果在加载包后定义了命令/环境的名称，它会用简单测试覆盖所使用的内部命令。

这并不完美，并且存在一些缺点：

如果您使用，它不会分离软件包\usepackage{foo,bar,baz}。它只是向您显示此命令由其中一个软件包加载。
它不能多次使用。需要更多逻辑才能同时搜索多个命令。

在加载任何其他包（以及文档类，如果您愿意的话）之前，像这样使用它：

\makeatletter
\newcommand*{\findpackagebycommand}[1]{
    … like above …
}
\makeatother

\findpackagebycommand{lstlisting}

\documentclass{article}

\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{listings}
\usepackage[T1]{fontenc}

\begin{document}

Test

\end{document}

包的名称将显示在 latex 输出中，行“包列表引入命令 lstlisting。”：

This is pdfTeX, Version 3.14159265-2.6-1.40.17 (TeX Live 2016/Arch Linux) (preloaded format=pdflatex)
 restricted \write18 enabled.
entering extended mode
(./packagetest.tex
[…]
(/usr/share/texmf-dist/tex/latex/base/inputenc.sty […])
(/usr/share/texmf-dist/tex/latex/amsmath/amsmath.sty […])
(/usr/share/texmf-dist/tex/latex/listings/listings.sty
(/usr/share/texmf-dist/tex/latex/graphics/keyval.sty)
(/usr/share/texmf-dist/tex/latex/listings/lstmisc.sty)
(/usr/share/texmf-dist/tex/latex/listings/listings.cfg))
Package listings introduces command lstlisting.
(/usr/share/texmf-dist/tex/latex/base/fontenc.sty
(/usr/share/texmf-dist/tex/latex/base/t1enc.def))
[…]

（当通过间接包加载（例如\define@key由某些包加载定义keyval）加载时，它会向后打印已加载包的链，但在不同的行。这可以改进。）

Answer 1