#!/opt/net/GNU/bin/perl -w
#
#      sends numbered UDP datagrams to a remote host.
#
#      Usage:
#          udp-send [-n <datagrams_number>] 
#                   [-s <datagrams_size>] 
#                   [-p <port_number>]
#                   host
#
#          <datagrams_number> defaults to 16, <datagram_size> to 32
#          and <port_number> to 9870.
#
# Renaud Waldura # on Sep 18 16:51:24 1995
#

require 'getopts.pl';


## parse options

&Getopts('n:s:p:') || die "Usage: $0 [-n <datagrams_number>] [-s <datagrams_size>] [-p <port_number>] host\n";

$opt_n = 16   unless $opt_n;
$opt_s = 32   unless $opt_s;
$opt_p = 9870 unless $opt_p;

($datagrams_number, $datagrams_size, $port) = ($opt_n, $opt_s, $opt_p);

$host = $ARGV[0];
die "Usage: $0 [-n <datagrams_number>] [-s <datagrams_size>] [-p <port_number>] host\n" unless $host;


## create a UDP socket

$sockaddr = 'S n a4 x8';	# magic
$family   = 2;			# AF_INET (system dependent !)
$socktype = 1;			# SOCK_DGRA (system dependent !)
chop($hostname = `/usr/ucb/hostname`);
#$hostname = "zork";

($name, $aliases, $proto) = getprotobyname('udp');
($name, $aliases, $type, $len, $my_addr  ) = gethostbyname($hostname);
print "gethostbyname($hostname) returns $name, $aliases, ...\n";
($name, $aliases, $type, $len, $peer_addr) = gethostbyname($host);
print "gethostbyname($host) returns $name, $aliases, ...\n";

$me   = pack($sockaddr, $family, 0,     $my_addr);
$peer = pack($sockaddr, $family, $port, $peer_addr);

# make the socket and  bind it to the protocol

socket(S, $family, $socktype, $proto) || die "Unable to create socket: $!";
bind(S, $me) || die "Unable to bind socket: $!";


## send numbered datagrams

foreach $n (1..$datagrams_number)
{
    $datagram = '*' x $datagrams_size . ":$n";

    send(S, $datagram, 0, $peer) || warn "Couldn't send: $!";
    print "Sent datagram $n, length = ", length($datagram), "\n";

    sleep(1);
}


## die
close(S);