#!/usr/bin/perl
use POSIX;

# The script prints only records for the last five minutes (300 seconds). The time interval is controlled by the delay parameter (specified in seconds).
my $delay = 300;

my $curtime = time();
my @months = ("Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec");

# In the cycle, time stamps are analyzed and only records that are included in the specified time interval are displayed.
# In the journal entries, the timestamps should be the same time zone where this script will run.
while (defined($line_ = <STDIN>)) {

	# Parsing the time stamp of the journal entry. This section must be edited for each individual log (because the structure of the time stamp record is different).
        $ib = index($line_,"[");
	$ie = index($line_,"]");
	$ds = substr($line_, $ib+1, $ie-$ib-1);

	my $day  = substr($ds, 0, 2);
	my $mon  = substr($ds, 3, 3);
	my $year = substr($ds, 7, 4);
	my $hour = substr($ds, 12, 2);
	my $min  = substr($ds, 15, 2);
	my $sec  = substr($ds, 18, 2);

	# Converting the month name to the serial number minus 1
	for  ($i = 0; $i < @months; $i++)  {
		last if $months[$i] eq $mon;
	}
	if ($i < @months) {
		$mon = $i;
	} else {
    		$mon = -1;
	}

	# Conversion of the year
	$year -= 1900;

	# Calculating the UnixTime timestamp of a journal entry
	my $logtime = mktime($sec, $min, $hour, $day, $mon, $year);

	print $line_ if ($logtime > ($curtime - $delay));
}