#! /usr/bin/perl
# to check ping from a file of hostnames using threads

#use strict;
use warnings;
use threads;
use threads::shared;
use Net::Ping;
use Time::HiRes;

my $timeout = 5;
my $ping_handle = Net::Ping->new("icmp",$timeout) or die "\n ping unsuccessful. $!";;
$ping_handle->hires();

#Get the host file name and check if valid file
print "\nEnter the host file name:";
chomp (my $host_file = <STDIN>);
open (HOSTFILE, "<", $host_file) or die "\nOpen of $host_file failed. $!";
#assign host_array to list of addresses in file and close
my @host_array = <HOSTFILE>;
close (HOSTFILE);

#Get output file name and check if valid file
print"\nEnter the output file name:";
chomp(my $out_file = <STDIN>);
open (OUTFILE, ">", $out_file) or die "\n Open of $out_file failed.$!";

#debugging
#if($ping_handle->ping("www.google.com")){
#	print "Google works\n";}
#else{
#	print "Ping not working\n";}

my @threads;

foreach $addr(@host_array){
	
	chomp($addr);	
	#print "$addr chomped off\n"; #debugging only
	
	my $thr = threads->new(\&sub_ping,$addr);
	sleep(1);
	push(@threads,$thr);
}

foreach (@threads){
	my $val = $_->join();
	print "Trying to ping $val complete\n"; 
}

sub sub_ping
{
	#check if host is a URL or an IP Address
	my $host= shift; #to get $ARGV[0]

	if (($host =~ m([a-zA-Z]+\.\w+\.\w+)) || ($host =~ m(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})))
	{
		($ret, $lat, $ip) = ($ping_handle->ping($host));
		#Check if the valid host responds to pings
		if ($ret)
		{
			printf "$host \($ip\) responds to pings at %.2f msec.\n",$lat*1000;
			printf OUTFILE ("$host \($ip\) responds to pings at %.2f msec.\n",$lat*1000);
		}
		else
		{
			printf "$host is NOT responding to pings. Time Taken %.2f msec\n",$lat*1000;
			printf OUTFILE ("$host is NOT responding to pings. Time taken %.2f msec\n",$lat*1000);
		}	
		$ping_handle->close();
	}
	else #the address is not a URL or an IP Address
	{
		print "$host is NOT a valid address.\n";
		print OUTFILE ("$host is NOT a valid address.\n");
	}
	return $host;
}