96 lines
4 KiB
Text
96 lines
4 KiB
Text
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% Copyright © 2022 Maximilian Keßler
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%
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% This work may be distributed and/or modified
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%
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% 1. under the LaTeX Project Public License and/or
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% 2. under the GNU General Public License
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%
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% Distribution under conditions of the LaTeX Project Public License,
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% requires either version 1.3 of this license or (at your option)
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% any later version.
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% The latest version of this license is in
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% http://www.latex-project.org/lppl.txt
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% and version 1.3 or later is part of all distributions of LaTeX
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% version 2005/12/01 or later.
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%
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% This work has the LPPL maintenance status \`maintained'.
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%
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% The Current Maintainer of this work is Maximilian Keßler.
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%
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%
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% Distribution under the GNU General Public License requires either
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% version 3 or (at your opinion) any later version.
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%
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% This package has been generated by PyTeX, available at
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% https://github.com/kesslermaximilian/PyTeX
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% and built from source file 'findpackage.pysty'.
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% It is STRONGLY DISCOURAGED to edit this source file directly, since local
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% changes will not be versioned by Git and overwritten by the next build. Always
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% edit the source file and build the package again.
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%
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% Build details:
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% PyTeX version: v1.2.0-30-g7542838 (commit 7542838)
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% Source code version: v2.8.1 (commit e2d4d57)
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%
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% This LaTeX package is free software and is dual-licensed
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% under the LPPLv1.3c and the GPLv3 licenses.
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% You may use it freely for your purposes.
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% The latest version of the package sources can be obtained
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% via GitLab under
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% https://gitlab.com/latexci/packages/LatexPackages
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% The latest version of the built packages can be obtained via GitLab under
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% https://gitlab.com/latexci/packages/LatexPackagesBuild
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% For further information see the urls above.
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% Reportings of bugs, suggestions and improvements are welcome, see the README
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% at the Git repository for further information.
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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\NeedsTeXFormat{LaTeX2e}
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\ProvidesPackage{mkessler-findpackage}[2022/01/30 - Find a package that provides some command]
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% This is just a quick packaging of the post by
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% 'Martin Nyolt' (https://tex.stackexchange.com/users/78783/martin-nyolt)
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% found at
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% https://tex.stackexchange.com/users/78783/martin-nyolt
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% Note that SO answers are by default CC BY-SA 3.0 licensed, see
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% https://creativecommons.org/licenses/by-sa/3.0/
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\def\find@load#1[#2]#3[#4]{%
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% load the package
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\find@fileswith@pti@ns{#1}[#2]{#3}[#4]%
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% check if commands exists now
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\ifcsname\find@command\endcsname
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\typeout{Package #3 introduces command \find@command.}%
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% command has been found, revert to original version without checks
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\let\@fileswith@pti@ns\find@fileswith@pti@ns
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\else
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% somehow, \@fileswith@pti@ns is restored after loading a package
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% thus, patch it again
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\let\@fileswith@pti@ns\find@load
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\fi
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}%
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\newcommand*{\findpackagebycommand}[1]{%
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% using this multiple times - esp. when the package has not been found yet -
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% will break things. Thus, check first that \find@command has never been defined before
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\ifx\find@command\undefined
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\def\find@command{#1}%
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% first, check if this command is already defined
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\ifcsname\find@command\endcsname
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% in this case, just issue a warning and do nothing
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\@latex@warning@no@line{Command \find@command \space is already defined}%
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\else
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% overwrite the internal \@fileswith@pti@ns command, which does the actual loading
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% \@fileswith@pti@ns is used internally by \usepackage and \RequirePackage
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\let\find@fileswith@pti@ns\@fileswith@pti@ns
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\let\@fileswith@pti@ns\find@load
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\fi
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\else
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% used multiple times - prevent and give a warning
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\@latex@warning@no@line{You can use \protect\findpackagebycommand \space only once}%
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\errmessage{Invalid use of command findpackagebycommand.}%
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\fi
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}
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