git-info.sty

% Experimental git-info package
\ProvidesPackage{git-info}[2009/06/13 v0.20 Using informations from git. (mpg)]

\RequirePackage{xkeyval}

% macros and tests for options
\newcommand\GI@max@depth{8}
\newcommand\GI@gih@name{git-info.gih}

\DeclareOptionX{maxdepth}{\renewcommand\GI@max@depth{#1}}
\DeclareOptionX{helper-file}{\renewcommand\GI@gih@name{#1}}

\ProcessOptionsX

% main user macro

\newcommand\gitinfo[2]{%
  \ifcsname GI@@#1@ok\endcsname
    \GI@gitinfo{#1}{#2}%
  \else
    \PackageError{git-info}{%
      No information available for #1}{%
      Possible causes are:\MessageBreak
      - for @head: you are not in a git repository.\MessageBreak
      - for @latest, @current, or a file: you did not\MessageBreak
      set up git-info-helper properly or forgot to\MessageBreak
      use \protect\gitfile{#1} or \protect\gitfile{<anything>}.}%
    \detokenize{(git-#1-#2)}%
  \fi}

\newcommand\GI@gitinfo[2]{%
  \GI@ifdt{#2}{%
    \GI@gitinfo@date{#1}{#2}%
    }{%
    \csname GI@@#1@#2\endcsname}}

\newcommand\GI@ifdt[1]{%
  \GI@ifdt@#1dt\@nil}
\@ifdefinable\GI@ifdt@{%
  \def\GI@ifdt@#1dt#2\@nil{%
    \GI@ifempty{#1}}}

\newcommand\GI@gitinfo@date[2]{%
  \expandafter\GI@gitinfo@date@\detokenize{#2@@}\@nil{#1}\@nil}
\@ifdefinable\GI@gitfinfo@date@{%
  \begingroup \edef\@tempa{\endgroup
    \def\noexpand\GI@gitinfo@date@
    \detokenize{dt@}##1\string @}\@tempa#2\@nil#3\@nil{%
    \csname GI@dtmac@#1\expandafter\expandafter\expandafter\endcsname
    \csname GI@@#3@datetime\endcsname}}

% private values
\newif\ifGI@is@a@repo@

% private constants
\newcommand\GI@repo@prefix{}
\newcommand\GI@head@file{\GI@repo@prefix/.git/HEAD}
\newcommand\GI@gih@file{\GI@repo@prefix/\GI@gih@name}
\@ifdefinable\GI@read{\let\GI@read\@inputcheck}

% \TeX{}nical tools

\newcommand\GI@ifempty[1]{%
  \expandafter\ifx\expandafter\relax\detokenize{#1}\relax
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi}

\newcommand\GI@export@macro[1]{%
  \edef\@tempa{\endgroup
    \def\noexpand#1{#1}}%
  \@tempa}

\newcommand\GI@set@export[2]{%
  \def\noexpand#1{\unexpanded\expandafter{#2}}}

\newcommand\GI@set@export@name[2]{%
  \expandafter\GI@set@export\csname #1\endcsname{#2}}

\newcommand\GI@safe@reading{%
  \let\do\@makeother \dospecials
  \catcode32 10
  \catcode09 12
  \endlinechar\m@ne
  \everyeof{\noexpand}}

% finding the .git directory

\newcommand\GI@check@repo@prefix{%
  \GI@is@a@repo@true
  \IfFileExists{./\GI@head@file}{%
    \edef\GI@repo@prefix{./}%
    }{%
    \GI@set@repo@prefix}}

\newcommand\GI@set@repo@prefix{%
  \begingroup \count@\GI@max@depth\relax
  \GI@set@repo@prefix@}

\newcommand\GI@set@repo@prefix@{%
  \advance\count@\m@ne
  \ifnum\count@<\z@
    \expandafter\GI@not@a@git@repo
  \else
    \edef\GI@repo@prefix{../\GI@repo@prefix}%
    \IfFileExists{\GI@head@file}{%
      \GI@export@macro\GI@repo@prefix
      }{%
      \expandafter\GI@set@repo@prefix@}%
  \fi}

\newcommand\GI@not@a@git@repo{%
  \endgroup
  \PackageWarningNoLine{git-info}{%
    Current directory is not a git repository.\MessageBreak
    \protect\gitinfo{@head} will NOT work}%
  \GI@is@a@repo@false
  \endinput}

% getting all informations about HEAD

\newcommand\GI@get@head@all{%
  \begingroup
  \GI@get@head@path
  \GI@get@branch
  \GI@get@head@hash
  \GI@get@head@infos
  \GI@compute@datetime
  \edef\@tempa{\endgroup
    \GI@set@export\GI@@@head@commit{\GI@head@commit}%
    \GI@set@export\GI@@@head@branch{\GI@head@branch}%
    \GI@set@export\GI@@@head@author{\GI@head@author}%
    \GI@set@export\GI@@@head@mail{\GI@head@mail}%
    \GI@set@export\GI@@@head@datetime{\GI@datetime}%
    \GI@set@export\GI@@@head@ok{\empty}}%
  \@tempa}

% finding the path to head

\newcommand\GI@get@head@path{%
  \openin\GI@read\GI@head@file
  \begingroup \GI@safe@reading
  \read\GI@read to\GI@head@file@contents
  \GI@export@macro\GI@head@file@contents
  \closein\GI@read
  \expandafter\GI@set@head@path\GI@head@file@contents\@nil}

\@ifdefinable\GI@set@head@path{%
  \begingroup 
  \GI@safe@reading
  \edef\@tempa{\endgroup
    \def\noexpand\GI@set@head@path\scantokens{ref:} }
  \@tempa#1\@nil{\def\GI@head@path{#1}}}

% extracting the branch name from the path to head

\newcommand\GI@get@branch{%
  \expandafter\GI@set@branch\GI@head@path\@nil}

 \@ifdefinable\GI@set@branch{%
   \def\GI@set@branch refs/heads/#1\@nil{%
     \def\GI@head@branch{#1}}}

% finding the hash (sha1) of head

\newcommand\GI@get@head@hash{%
  \openin\GI@read\GI@repo@prefix/.git/\GI@head@path
  \begingroup \GI@safe@reading
  \read\GI@read to\GI@head@hash
  \GI@export@macro\GI@head@hash
  \closein\GI@read}

% finding head commit infos

\newcommand\GI@get@head@infos{%
  \openin\GI@read\GI@repo@prefix/.git/logs/\GI@head@path
  \begingroup \GI@safe@reading
  \GI@get@head@infos@loop}

\count@\catcode09 \catcode09 12
\newcommand\GI@get@head@infos@loop{%
  \read\GI@read to\GI@log@line
  \expandafter\GI@infos@from@line\GI@log@line^^09\@nil
  \ifx\GI@commit\GI@head@hash
    \expandafter\GI@get@head@infos@end
  \else
    \expandafter\GI@get@head@infos@loop
  \fi}

\@ifdefinable\GI@infos@from@line{%
  \def\GI@infos@from@line#1 #2 #3 <#4> #5 #6^^09#7\@nil{%
    \def\GI@commit{#2}%
    \def\GI@name{#3}%
    \def\GI@mail{#4}%
    \def\GI@timestamp{#5}%
    \def\GI@timezone{#6}%
    % GI@what currently unused
    % (don't forget to remove the spurious tab before using it latter)
    \def\GI@what{#7}}}
\catcode09\count@

\newcommand\GI@get@head@infos@end{%
  \closein\GI@read
  \edef\@tempa{\endgroup
    \GI@set@export\GI@timestamp{\GI@timestamp}%
    \GI@set@export\GI@timezone{\GI@timezone}%
    \GI@set@export\GI@head@commit{\GI@commit}%
    \GI@set@export\GI@head@author{\GI@name}%
    \GI@set@export\GI@head@mail{\GI@mail}}%
  \@tempa}

% time conversions

% a = quotient(a, b) * b + remainder(a, b)
% with 0 <= remainder(a, b) < abs(b)
% assumes a >= 0 and b > 0
\newcommand\GI@int@quotient[2]{%
  \ifnum\numexpr#1=\z@ \z@ \else \numexpr(#1-((#2-1)/2))/#2\relax \fi}
\newcommand\GI@int@remainder[2]{%
  \numexpr#1-\GI@int@quotient{#1}{#2}*#2\relax}

% #1 = cs to define, #2 = modulo; sets \count@ too
\newcommand\GI@extract@units[2]{%
  \edef#1{\number\GI@int@remainder{\count@}{#2}}%
  \divide\count@#2\relax}

% #1 = nb of year since epoch, result = nb of days since epoch
% Ex: 0 => 0, 365, 730, 1096, 1461, ...
\newcommand\GI@years@to@days[1]{%
  \numexpr365*(#1)+\GI@int@quotient{#1+1}{4}\relax}

% \count@ = days since epoch (before), day of year (after)
\newcommand\GI@extract@year{%
  \edef\GI@year{\number\numexpr\GI@int@quotient{\count@}{365}%
    +\ifnum\count@<\GI@years@to@days{%
      \GI@int@quotient{\count@}{365}}1969 \else1970 \fi}%
  \advance\count@-\number\GI@years@to@days{\GI@year-1970}\relax}

% sets month and day of month
\newcommand\GI@extract@month@day{%
  \ifnum\GI@int@remainder{\GI@year}{4}=\z@
    \ifnum\count@>58
      \ifnum\count@=59 \def\GI@hook{\def\GI@day{29}} \fi
      \advance\count@\m@ne
    \fi
  \fi
  \countdef\GI@month\tw@ \GI@month\@ne
  \@for\GI@month@length:=31,28,31,30,31,30,31,31,30,31,30,31\do{%
    \GI@extract@month@day@loop}%
  \csname GI@hook\endcsname}

\newcommand\GI@extract@month@day@loop{%
  \ifnum\count@<\GI@month@length\relax
    \edef\GI@day{\number\numexpr1+\count@}%
    \let\GI@extract@month@day@loop\relax
  \else
    \advance\GI@month\@ne
    \advance\count@-\GI@month@length
  \fi}

\newcommand\GI@compute@datetime{%
  \begingroup
  \expandafter\expandafter\expandafter
  \GI@parse@timezone\csname GI@timezone\endcsname
  \count@\numexpr\csname GI@timestamp\endcsname
    \GI@tzsign((\GI@tzhour*60+\GI@tzmin)*60)\relax
  \GI@extract@units\GI@sec{60}%
  \GI@extract@units\GI@min{60}%
  \GI@extract@units\GI@hour{24}%
  \GI@extract@year
  \GI@extract@month@day
  \edef\GI@datetime{%
    {\GI@year}{\GI@two@d{\the\GI@month}}{\GI@two@d\GI@day}%
    {\GI@two@d\GI@hour}{\GI@two@d\GI@min}{\GI@two@d\GI@sec}%
    {\GI@tzsign}{\GI@two@d\GI@tzhour}{\GI@two@d\GI@tzmin}}%
  \edef\@tempa{\endgroup
    \GI@set@export@name{GI@datetime}{\GI@datetime}}
  \@tempa}

\newcommand\GI@parse@timezone[5]{%
  \def\GI@tzsign{#1}%
  \def\GI@tzhour{#2#3}%
  \def\GI@tzmin{#4#5}}

\newcommand\GI@two@d[1]{%
  \ifnum#1<10 0\number#1\else \number#1\fi}

% displaying date - defining user macros

\newcommand\gitNewDateFormat[2]{%
  \expandafter\newcommand\csname GI@dtmac@#1\endcsname[9]{#2}}

\gitNewDateFormat{}         {#1-#2-#3 #4:#5}
\gitNewDateFormat{datetime} {#1-#2-#3T#4:#5:#6#7#8:#9}
\gitNewDateFormat{date}     {#1-#2-#3}
\gitNewDateFormat{time}     {#4:#5:#6}
\gitNewDateFormat{timezone} {#7#8:#9}

\gitNewDateFormat{today}{%
  \@ifundefined{today}{%
    \PackageError{git-info}{%
      \noexpand\today undefined! Did you load babel?}{%
      You cannot use \noexpand\gitXXXtoday macros if
      \noexpand\today is undefined.\MessageBreak
      This macro is usually defined by the babel package.}%
    }{%
    \begingroup
    \year#1 \month#2 \day#3
    \today
    \endgroup}}

% main

\GI@check@repo@prefix
\ifGI@is@a@repo@
  \GI@get@head@all
\fi