% Dated footer style (for LaTeX2e)

% This style redefines the empty, plain and headers pagestyles to include a
% date stamp in the footer.
%
% The date is the current date, or optionally from the date string from a
% revision control system (rcs) keyword string.  The user can directly set the
% date stamp value using the macro \datestamp.  The default form for the date
% is "1996/08/02".
%
% options:
%   all (default) - The date stamp is placed on all pages.
%   first - The date stamp is placed only on the first page of the main
%     document, and on the first page of any \included files.
%   off - The date stamp is turned off.  This option suppresses printing of
%     the date stamp without the need to remove all datestamp commands (such
%     as \rcs).
%
% The datestamp value can be controlled with the \datestamp macro.
%   \datestamp [datestamp-string] - Set the date stamp value, overriding the
%   current date or date derived from the \rcs macro.  If the optional
%   datestamp-string is omitted, the current date is used.
%
% Files under rcs control:
%   For a file under rcs control is that the date stamp that appears on the
%   document is the time of the document modification and not that of the time
%   of printing.  To use the rcs date, the user invokes the \rcs macro which
%   takes as an argument an rcs keyword string.  The date is taken from the
%   rcs keyword string only if the keyword string indicates that the file is
%   checked in, i.e. not checked out by rcs for modification.
%
%   This style defines the macro \rcs.  The user places a revision control
%   system (rcs) keyword string in the source file at a point after this
%   package is invoked.
%     \rcs{#Id: #}	%  Use "$" instead of "#"; the example has to use #
%			%  instead of $ to avoid having rcs place the
%			%  keyword string in the text of the example.
%   The Id keyword string is replaced by rcs with one of the following form.
%     \rcs{$Id: datestamp.sty,v 1.12 1997/08/26 13:01:47 kabal Exp $}
%
% Included files:
%   For each file invoked with "\include", the date stamp is reset to the
%   current date.  An "\rcs" command in the included file can be used to
%   change the date stamp for that file.
%
% Date Stamp Format:
%   This package changes the standard LaTeX pagestyles to include a date
%   stamp in the footer:
%   pagestyle "plain"
%    - left justified date stamp with centered page number in footer
%   pagestyle "empty"
%    - left justified date stamp in footer
%   pagestyle "headers"
%    - left justified date stamp in footer
%
% Notes:
%   The \datestampbox macro defines a zero-sized box containing the datestamp.
%   This can be included in the footer of a custom page layout.  For instance
%   it can be used with the fancyhdr package,
%     \fancyfoot[LO,RE]{\datestampbox}
%
%   The \datestampoffset dimen variable can be used to control the vertical
%   position of the date stamp.  For printers that do not allow printing close
%   to the edge of the paper, or for documents in which the footer comes very
%   close to the bottom of the physical page, this value may have to be
%   changed.  The default value is 5ex.
%

% $Id: datestamp.sty,v 1.12 1997/08/26 13:01:47 kabal Exp $

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{datestamp}[1996/12/27]

% date stamp format
\newdimen\datestampoffset
\datestampoffset = 5ex
\def\datestampfont{\reset@font\bfseries\scriptsize}

% date stamp box
\newcount\datestampcount
\global\datestampcount=0
\newcount\datestamplimit

\def\datestampbox{%
  \global\advance \datestampcount by 1
  \ifnum \datestampcount > \datestamplimit
  \else
    \leavevmode\lower \datestampoffset \hbox to 0pt{\datestampfont \@datestamp
                                         \hskip 0pt minus 1fil\relax}%
  \fi}

% Set up the options
\DeclareOption{off}{\datestamplimit=0}
\DeclareOption{first}{\datestamplimit=1}
\DeclareOption{all}{\datestamplimit=999999}

\ExecuteOptions{all}
\ProcessOptions

% Set up the page styles include the date in the footer
\let\SVps@empty=\ps@empty
\def\ps@empty{\SVps@empty
     \def\@oddfoot{\datestampbox\hfil}%
     \let\@evenfoot\@oddfoot}
\let\SVps@plain=\ps@plain
\def\ps@plain{\SVps@plain
     \def\@oddfoot{\datestampbox\reset@font\hfil\thepage\hfil}%
     \let\@evenfoot\@oddfoot}
\let\SVps@headings=\ps@headings
\def\ps@headings{\SVps@headings
     \def\@oddfoot{\datestampbox\hfil}%
     \let\@evenfoot\@oddfoot}

% Set the date in the footer immediately
\let\df@even=\@evenfoot
\let\df@odd=\@oddfoot
\def\@evenfoot{\datestampbox\df@even}%
\def\@oddfoot{\datestampbox\df@odd}%

% Redefine \include to reset the datestamp (\include cannot be nested)
% Notes: the \include macro essentially expands to
%    \clearpage \input xxx.tex \clearpage
%    Here we force a \clearpage or \cleardoublepage (depending on the setting
%    of the openright/openany options and reset the datestamp counters before
%    invoking the code for the original \include macro.  The \clearpage inside
%    the original \include macro is then a no-op, as is any \clearpage or
%    \cleardoublepage inside a \chapter macro.
\let\SVinclude=\include
\def\cdp{\if@openright
           \cleardoublepage
         \else
           \clearpage
         \fi}
\def\include #1{\ifx\if@openright\@undefined
                  \clearpage
                \else
                  \cdp		% Hide the \if@openright for proper nesting
                \fi
                \edef\SV@ds{\@datestamp}
                \setdatestampvalue\relax
                \edef\SVdscount{\the\datestampcount}
                \global\datestampcount=0
                \SVinclude {#1}%
                \setdatestampvalue[\SV@ds]%
                \global\datestampcount=\SVdscount}

% Set the date stamp value
\newcommand \setdatestampvalue
  [1][\the\year/\two@digits{\the\month}/\two@digits{\the\day}]{%
  \def\@datestamp{#1}}
\setdatestampvalue \relax
\let \datestamp = \setdatestampvalue

% Macro to define \@date using the date from the rcs keyword string
\def\rcs #1{\df@idparse |#1 $ = = - - $ $ |}
\def\df@idparse |#1 #2 #3 #4 #5 #6 #7 #8 #9|{%
  \ifx #4=%
  \else
    \ifx #8$%
      \typeout{File: \df@fname |#2,v|, revision #3 #4}%
      \setdatestampvalue [#4]%
    \else
      \typeout{File: \df@fname |#2,v|, revision #3 #4 locked}%
      \setdatestampvalue \relax
    \fi
  \fi}
\def\df@fname|#1,v#2|{#1}