由 markdown 转换而来的 latex 中的链接和参考链接

Question

问题在于 URL 应该被逐字读取。

如果你有兴趣我可以提供一个界面

\urllabel{⟨referencing-label⟩}⟨verbatim-argument denoting url⟩

和

\urllink{⟨link text⟩}{⟨referencing-label⟩}

其中\urllabel读⟨表示 url 的逐字参数⟩在 verbatim-catcode-régime 下，并将其复制到 .aux 文件，以便可以在文档的任何地方引用它\urlref。在引用时\urllink 传递⟨表示 url 的逐字参数⟩到\href。

该机制基于 kernel-macro \@newl@bel，但带有一些用于在 verbatim-catcode-régime 下复制/读取参数的包装器。这样，您会收到有关多次定义标签和标签被更改的警告。（\@setref无法使用，但需要以类似方式实现，因为 hyperref 已重新定义。）

（如果 xparser 提供了在读取 av/+v 参数时获取逐字分隔符的方法，则可以通过 xparser 轻松实现这一点。）

注意事项：

在第一次 LaTeX 运行中，虽然不存在 .aux 文件，但交叉引用标签/动词标签未定义，因此您无法获得超链接。
您至少需要进行两次编译，直到所有内容匹配为止。
类似于\verb其他期望其参数在非标准 catcode 制度中被标记的宏，\urllabel不能在其他宏的参数或定义文本中使用。
接口使用 .aux 文件。因此，如果 TeX 发行版中的某些字符以 ^^ 符号写入 .aux 文件（例如，由于 character-translation/tcx-files），则可能会引发问题。

\makeatletter
%%======================Code for \UDcollectverbarg=============================
%% \UDcollectverbarg{<non-optional 1>}{<non-optional 2>}|<verbatim arg>|
%% 
%% reads <verbatim arg> under verbatim-catcode-regime and delivers:
%%
%%    <non-optional 1>{<non-optional 2>{<verbatim arg>}}
%%-----------------------------------------------------------------------------
%% \UDcollectverbarg*{<non-optional 1>}{<non-optional 2>}|<verbatim arg>|
%% 
%% reads <verbatim arg> under verbatim-catcode-regime and delivers:
%%
%%    <non-optional 1>{<non-optional 2>{|<verbatim arg>|}}
%%-----------------------------------------------------------------------------
%% Instead of using verbatim-delimiter | or the like the <verbatim arg> can 
%% be nested in braces.
%%
%% You cannot use percent or spaces or horizontal tab as verbatim-delimiter.
%%
%% You can use <non-optional 1> for nesting calls to \UDcollectverbarg.
%%
%% The unstarred variant removes the verbatim-delimiters/braces that surround
%% <verbatim arg>.
%% The starred variant keeps the verbatim-delimiters/braces that surround
%% <verbatim arg>.
%% Reason: When you feed things to \scantokens you don't need the verbatim-
%%         delimiters.
%%         When you use things for writing to temporary files and reading back
%%         verbatimized, you may need them.
%%=============================================================================
\@ifdefinable\UDcollectverbarg{%
  \DeclareRobustCommand\UDcollectverbarg{%
    \@ifstar{\UD@collectverbarg{\@secondoftwo}}{\UD@collectverbarg{\@firstoftwo}}%
  }%
}%
\newcommand\UD@collectverbarg[3]{%
  % #1 - indicator whether to remove/keep the verb-delimiter (\@firstoftwo/\@secondoftwo)
  % #2 - non-optional 1
  % #3 - non-optional 2
  \begingroup
  \let\do\@makeother % <- this and the next line switch to
  \dospecials        %    verbatim-category-code-régime.
  \catcode`\{=1      % <- give opening curly brace the usual catcode so a 
                     %    curly-brace-balanced argument can be gathered in
                     %    case of the first thing of the verbatimized-argument 
                     %    being a curly opening brace.
  \catcode`\ =10     % <- give space and horizontal tab the usual catcode so \UD@@collectverbarg
  \catcode`\^^I=10   %    cannot catch a space or a horizontal tab as its 4th undelimited argument.
                     %    (Its 4th undelimited argument denotes the verbatim-
                     %     syntax-delimiter in case of not gathering a
                     %     curly-brace-nested argument.)
  \catcode`\%=14     % <- make percent comment.
  \kernel@ifnextchar\bgroup
  {% seems a curly-brace-nested argument is to be picked:
    \catcode`\}=2    % <- give closing curly brace the usual catcode also.
    \UD@@collectverbarg{#1}{\@firstoftwo}{#2}{#3}{}%
  }{% seems an argument with verbatim-syntax-delimiter is to be picked:
    \do\{% <- give opening curly brace the verbatim-catcode again.
    \UD@@collectverbarg{#1}{\@secondoftwo}{#2}{#3}%
  }%
}%
\newcommand\UD@@collectverbarg[5]{%
  % #1 - indicator whether to remove/keep the verb-delimiter (\@firstoftwo/\@secondoftwo)
  % #2 - indicator whether braces or verb-delimiter (\@firstoftwo/\@secondoftwo)
  % #3 - non-optional 1
  % #4 - non-optional 2
  % #5 - verb-delimiter or emptiness
  \do\ %   <- Now that \UD@@collectverbarg has the delimiter or
  \do\^^I%    emptiness in its 4th arg, give space and horizontal tab
         %    the verbatim-catcode again.
  \do\^^M% <- Give the carriage-return-character the verbatim-catcode.
  \do\%%   <- Give the percent-character the verbatim-catcode.
  \long\def\@tempb##1#5{%
    #1{\def\@tempb{##1}}{#2{\def\@tempb{{##1}}}{\def\@tempb{#5##1#5}}}%
    \@onelevel@sanitize\@tempb % <- Turn characters into their "12/other"-pendants.
                               %    This may be important with things like the 
                               %    inputenc-package which may make characters 
                               %    active/which give them catcode 13(active).
    \expandafter\UD@@@collectverbarg\expandafter{\@tempb}{#3}{#4}% <- this "spits out the result.
  }%
  \@tempb
}%
\newcommand\UD@@@collectverbarg[3]{\endgroup#2{#3{#1}}}%
%%================= End of code for \UDcollectverbarg =========================
%%
\DeclareRobustCommand\urllabel[1]{%
  \@bsphack\UDcollectverbarg*{\@firstofone}{\UD@writeverblabel{#1}}%
}%
\newcommand\UD@writeverblabel[2]{%
  \begingroup
  \newlinechar=\endlinechar
  \immediate\write\@auxout{\string\newverblabel{#1}#2\@percentchar}%
  \endgroup
  \@esphack
}%
\newcommand\newverblabel[1]{%
  \UDcollectverbarg{\@firstofone}{\UD@defineverblabel{#1}}%
}%
\newcommand\UD@defineverblabel[2]{\@newl@bel{vrblbl}{#1}{#2}}%
\DeclareRobustCommand\urlref[2]{%
  \expandafter\ifx\csname vrblbl@#2\endcsname\relax 
    \protect\G@refundefinedtrue
    \@latex@warning {Reference `#2' on page \thepage\space undefined}%
    #1%
  \else 
    \expandafter\expandafter\expandafter\href
    \expandafter\expandafter\expandafter{\csname vrblbl@#2\expandafter\endcsname}{#1}%
  \fi
}%
\makeatother

\documentclass{article}

\usepackage{hyperref}

\begin{document}

Some text.

\urlref{CTAN}{2} is an important resource for users of \TeX.

\urlref{TeX LaTeX StackExchange is a question-answer-platform.}{TeXLaTeXStackExchange}

Some more text.

%-------------------------------------------------------------------

\urllabel{TeXLaTeXStackExchange}|https://tex.stackexchange.com/|
\urllabel{2}|https://ctan.org/|

\end{document}

Answer 1