#!/usr/local/bin/perl -slw

use strict;
use Date::Manip;
use Data::Dumper;

my $now = ParseDate( scalar localtime());
print "now is $now<p>";
my $then = DateCalc( $now, ParseDateDelta( "7 hours 48 minutes ago" ));
my $err;

open LOGFILE, "datafile.html" || die "Can't open file";

my $re = qr/
    ^.*?                    # Skip the first part
    \[([^\]]+)\]\s+            # capture everything between []
    "[^"]+"\s+                # skip a quoted string and whitespace
    .*?                        # and a couple of numbers or blanks
    "( [^"]+ )"                # capture the next quoted string
/x;

my %referrers;
while(<LOGFILE>) {
    my @chunks = /$re/;
    my $ts = ParseDate $chunks[0];
    print "The line '@chunks' was logged ",
        Delta_Format( DateCalc( $ts, $now, \$err ), 2, ("%mt")),
        " minutes ago.";
    if ( Date_Cmp( $ts, $then ) > 0
    and  Date_Cmp( $ts, $now  ) < 0 ) {
        print "The previous line is within the window. Counting...";
        $referrers{$chunks[1]}++;
    }
    else {
        print "Discarding previous line";
    }
}

print "\nThese are the referrers counted:\n", Dumper(\%referrers);