gno/doc/etc/getdate

#! /usr/bin/perl -s
#
# Extract the date from the RCS Id string in a file.
#
# $Id: getdate,v 1.1 2012/08/26 02:27:36 gdr Exp $
#

use strict;

my @month;
push(@month,
     "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
     "Oct", "Nov", "Dec" );

# for ($i=0; $i<12; $i++) {
#     printf("month %d is %s\n", $i, $month[$i]);
# }

my $printdate = 0;
my $printversion = 0;

if (defined($::date)) {
    $printdate = 1;
}
if (defined($::version)) {
    $printversion = 1;
}

my %sortedDates;
my %sortedVersions;

my $date = "(unspecified date)";
my $version = "(unspecified version)";

while(<>) {
    if (/\$Id([^\$]*)\$/) {
	$_ = $1;

	if (/^:\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+/) {
	    my $file=$1;
	    my $v=$2;
	    my $rawdate=$3;
	    my $time=$4;
	    if ($rawdate =~ m,(\d+)[-/](\d+)[-/](\d+),) {
		my $year = $1;
		my $m = $2;
		my $day = $3;
		my $mon = @month[int($2) - 1];
		my $d = "$day $mon $year";
		my $fakedate = int($day) + 100 * int($m) + 10000 * int($year);
		$sortedDates{"$fakedate"} = $d;
		$sortedVersions{"$fakedate"} = $v;
	    }
	}
    }
}

my @fakes = sort(keys(%sortedDates));
my $lastFake = pop @fakes;
if (defined($lastFake)) {
    $date = $sortedDates{$lastFake};
    $version = $sortedVersions{$lastFake};
}

if ($printdate) {
    printf("%s\n", $date);
} elsif ($printversion) {
    printf("%s\n", $version);
} else {
    printf("getdate: bad invocation\n");
    exit(1);
}

exit(0);