#!/usr/bin/perl -w
use strict;
use Date::Calc qw(Mktime Today_and_Now Delta_DHMS);

my @starttime = Today_and_Now;
print "Begin Index\n";
open (BIGLOG, "< D:/Logs/biglog.unsorted.log")
	|| die "Cannot open log\n";

my @index;

while (<BIGLOG>){
    my $offset = tell BIGLOG;
    my $epoch = ( /^\s*#/ or /^\s\n/ or $_ !~ /^\s*\d/ ) ? 0 
        : Mktime( unpack 'A4xA2xA2xA2xA2xA2', $_  );
    push @index, pack 'NN', $epoch, $offset;
}

print "\nIndexed ". @index ." Lines in ";
printf "%02d Days, %02d Hours, %02d Minutes, %02d Seconds\n", Delta_DHMS( @starttime, Today_and_Now );

print "Begin Sort\n";
my @startsort = Today_and_Now;
@index = sort {$a cmp $b} @index;

print "Sorted ". @index ." Lines in ";
printf "%02d Days, %02d Hours, %02d Minutes, %02d Seconds\n", Delta_DHMS( @startsort, Today_and_Now );

open (OUTFILE, "> D:/Logs/biglog.sorted.log") || die;
foreach (@index){
	my $byte = unpack( 'N',substr( $_, 4, 4 ));
	print OUTFILE readline_n(\*BIGLOG, $byte ) ||
		warn unpack( 'N', substr( $_, 0, 4 )).":".unpack( 'N',substr( $_, 4, 4 )).$!;
}

close OUTFILE;
close BIGLOG;

print "\nTotal runtime:\t\t";
printf "%02d Days, %02d Hours, %02d Minutes, %02d Seconds\n", Delta_DHMS( @starttime, Today_and_Now);

exit;

sub readline_n{
	my( $fh, $line) = @_; 
	seek $fh, $line, 0;
	scalar <$fh> 
}