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

my @starttime = Today_and_Now;

open (BIGLOG, "< E:/biglog.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;
}

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

@index = sort @index;

my @endtime = Today_and_Now;

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

close BIGLOG;
exit;

sub readline_n{ 
    my( $fh, $line) = @_; 
    seek $fh, unpack( 'x[N]N', $line ), 0;
    scalar <$fh> 
}