LaTeX-proposal/bin/filedate

#!/usr/bin/perl -w
#######################################################################################
# A tool for updating .dtx files with a given package date.                           #
# Copyright (c) 2010, Deyan Ginev, released under the Gnu General Public License (GPL)#
#                                 see http://www.gnu.org/copyleft/gpl.html            #
#######################################################################################

use strict;

use Getopt::Long;
use Modparse;
use Pod::Usage;
use Cwd qw(abs_path);

my ($file) = @ARGV;
my $date = `git log --format='%ai' $file`;
$date = substr($date, 0, index($date, ' '));
$date =~ s/-/\//g;
$file = abs_path($file);
open(IN,"<$file");
my @lines = ();
while (<IN>) {
  if ($_ =~ /\\Provides(Package|Class)/) {
    $_ =~ s/\[(.*?)\s/\[$date /;
  }
  push @lines, $_;
}
close(IN);
open(OUT,">$file");
print OUT join("",@lines);
close(OUT);

__END__


=head1 SYNOPSIS

filedate <input filename> <newdate>

Purpose:
    Update the dates for a \ProvidePackage invocation in a given .dtx source

Example:
    filedate omdoc.dtx