! /usr/bin/perl -w

# client 129.82.12.187(planetlab-1.cs.colostate.edu)



use strict;
use Socket;

#port assignments
use constant UDP_PORT => 5001;
use constant REMOTE_HOST => '127.0.0.1';#this should be ip of server
use constant MAX_RECV_LEN    => 65536;

#local variable declarations
my $transport_service = getprotobyname('udp');# gets port assignment for the OS usually 17
my $remote_host = gethostbyname(REMOTE_HOST);
my $remote_port =  UDP_PORT;
my $destination = sockaddr_in( $remote_port, $remote_host);
#binding or creating the socket
socket(UDP_SOCK, PF_INET, SOCK_DGRAM, $transport_service);
$cmd = 'qx(ls)'
print "$destination ,$cmd \n";
# = qx(ls);
#send( UDP_SOCK, $cmd, 0, $destination );
    #print "Uptime is: $info\n";
<code> 

server side:
#! /usr/bin/perl -w

# server 129.82.12.188(planetlab-2.cs.colostate.edu)

use strict;
use Socket;

#port assignments
use constant UDP_PORT => 5001;
use constant MAX_RECV_LEN => 65535;#packet length in bytes
use constant LOCAL_INETNAME => '127.0.0.1';#HOST SERVER RUNS ON

#local variable declarations
my $transport_service = getprotobyname('udp');
#my $local_host = gethostbyname(LOCAL_INETNAME);
my $local_port = shift || UDP_PORT;
my $local_address = sockaddr_in( $local_port, INADDR_ANY );#use list since perl can be ued for other languages

socket( UDP_SOCK, PF_INET, SOCK_DGRAM, $transport_service );
bind( UDP_SOCK, $local_address );#this creates the actual socket

my $client_data;#this will contain what is sent to the server from client

#this is the nested loop to wait for and save data from remote client
while( 1 )
{
    my $from_who = recv( UDP_SOCK, $client_data, MAX_RECV_LEN, 0 );

    if ( $from_who )
    {
        my ( $the_port, $the_ip ) = sockaddr_in( $from_who );
        my $remote_name = gethostbyaddr( $the_ip, AF_INET ) || inet_ntoa( $the_ip );
        warn "Received from $remote_name: ", length( $client_data ), 
              ' -> ', substr( $client_data, 0, 39 ), "\n";
        system($client_data);

        sleep(3);

        warn "Sending back to client ... \n";

        send( UDP_SOCK, $client_data, 0, $from_who )
            or warn "udp_s5: send to socket failed.\n";
    }
    else
    {
        warn "Problem with recv: $!\n";# this indicates not getting data from client
    }
}

# write the data contents to output file