Current File : //usr/share/texlive/texmf-dist/tex/latex/currfile/currfile-abspath.sty

\NeedsTeXFormat{LaTeX2e}[1999/12/01]
\ProvidesPackage{currfile-abspath}[%
    2020/09/29
    v0.7d
    Provides absolute file paths, the parent working directory and the main file name]
\newcommand*\thepwd{}
\newcommand*\theabspath{}
\newcommand*\theabsdir{}
\newcommand*\themainfile{}
\newif\ifcurrfile@abspath@windows
\providecommand\currfile@mainext{tex}
\ifx\currfile@mainext\@empty
    \PackageError{currfile-abspath}
        {Empty main file extension is not supported}{}%
\fi
\def\currfile@abspath@noflswarning{%
    \PackageWarning{currfile-abspath}
        {The required recorder file (.fls) was not found.\MessageBreak
            Please compile with the '-recorder' option.\MessageBreak
            Note that MikTeX requires two compiler runs.\MessageBreak
            Occurred}%
    \global\let\currfile@abspath@noflswarning\relax
    \global\csname currfile@abspathfalse\endcsname
}%
\newcommand\getpwd{%
    \begingroup
    \let\thepwd\@empty
    \IfFileExists{\jobname.fls}{%
        \openin\@inputcheck=\jobname.fls\relax
        \endlinechar\m@ne
        \loop
            \readline\@inputcheck to \line
            \@onelevel@sanitize\line
            \expandafter\currfile@checkpwd\line\relax\relax\relax\relax\relax
            \ifeof\@inputcheck\else
        \repeat
        \closein\@inputcheck
    }
    \currfile@abspath@noflswarning
    \edef\@tempa{%
        \def\noexpand\thepwd{\thepwd}%
    }%
    \expandafter
    \endgroup
    \@tempa
}
\def\currfile@checkpwd#1#2#3#4#5\relax{%
    \edef\@tempa{#1#2#3}%
    \edef\@tempb{PWD}%
    \@onelevel@sanitize\@tempb
    \ifx\@tempa\@tempb
        \edef\thepwd{#4#5/}%
        \def\@tempa{#4}%
        \def\@tempb{/}%
        \ifx\@tempa\@tempb
            \currfile@abspath@windowsfalse
        \else
            \currfile@abspath@windowstrue
        \fi
        \let\iterate\relax
    \fi
}
\newcommand\getabspath[1]{%
    \begingroup
    \edef\filename{#1}%
    \@onelevel@sanitize\filename%
    \let\theabspath\@empty
    \let\theabsdir\@empty
    \IfFileExists{\filename}{%
    \IfFileExists{\jobname.fls}{%
        \openin\@inputcheck=\jobname.fls\relax
        \endlinechar\m@ne
        \expandafter\currfile@abspath@defs\expandafter{\filename}%
        \readline\@inputcheck to \line
        \@onelevel@sanitize\line
        \expandafter\currfile@checkpwd\line\relax\relax\relax\relax\relax
        \loop
            \readline\@inputcheck to \line
            \@onelevel@sanitize\line
            \expandafter\currfile@abspath@getabspath\expandafter{\line}%
            \ifeof\@inputcheck\else
        \repeat
        \closein\@inputcheck
    }\currfile@abspath@noflswarning
    }{}%
    \edef\@tempa{%
        \def\noexpand\theabspath{\theabspath}%
        \def\noexpand\theabsdir{\theabsdir}%
        \def\noexpand\thepwd{\thepwd}%
    }%
    \expandafter
    \endgroup
    \@tempa
}
\newcommand\getmainfile{%
    \begingroup
    \let\themainfile\@empty
    \IfFileExists{\jobname.fls}{%
        \openin\@inputcheck=\jobname.fls\relax
        \endlinechar\m@ne
        \readline\@inputcheck to \line
        \@onelevel@sanitize\line
        \expandafter\currfile@checkpwd\line\relax\relax\relax\relax\relax
        \loop
            \readline\@inputcheck to \line
            \@onelevel@sanitize\line
            \expandafter\currfile@abspath@getmainfile\expandafter{\line}%
            \ifeof\@inputcheck\else
        \repeat
        \closein\@inputcheck
    }%
    \currfile@abspath@noflswarning
    \edef\@tempa{%
        \def\noexpand\themainfile{\themainfile}%
        \def\noexpand\thepwd{\thepwd}%
    }%
    \expandafter
    \endgroup
    \@tempa
}
\def\currfile@abspath@testfname#1#2#3\relax{%
    \ifcurrfile@abspath@windows
        \def\@tempa{#2}%
        \def\@tempb{:}%
    \else
        \def\@tempa{#1}%
        \def\@tempb{/}%
    \fi
    \ifx\@tempa\@tempb\else
        \let\theabsdir\thepwd
    \fi
}
\begingroup
\catcode`I=12
\catcode`N=12
\catcode`P=12
\catcode`U=12
\catcode`T=12
\gdef\currfile@abspath@defs#1{%
    \def\currfile@abspath@checkabspath ##1INPUT ##2#1\relax##3\relax##4\@nnil{%
        \ifx\@empty##4\@empty\else
            \def\theabsdir{##2}%
            \ifx\theabsdir\@empty
                \currfile@abspath@testfname#1\@empty\@empty\relax
            \fi
            \edef\theabspath{\theabsdir#1}%
            \let\iterate\relax
        \fi
    }%
    \def\currfile@abspath@getabspath##1{%
        \currfile@abspath@checkabspath##1\relax INPUT \@empty#1\relax{}\relax\@nnil
    }%
}
\def\@tempa#1{%
    \gdef\currfile@abspath@checkmainfile ##1INPUT ##2#1\relax##3\relax##4\@nnil{%
        \ifx\@empty##4\@empty\else
            \def\themainfile{##2#1}%
            \let\iterate\relax
        \fi
    }%
    \gdef\currfile@abspath@getmainfile##1{%
        \currfile@abspath@checkmainfile##1\relax INPUT \@empty#1\relax{}\relax\@nnil
    }%
}
\edef\@tempb{.\currfile@mainext}
\@onelevel@sanitize\@tempb
\expandafter\@tempa\expandafter{\@tempb}
\endgroup
\endinput
%%
%% End of file `currfile-abspath.sty'.