package SoServ; #: one server for all clients

	use IO::Socket::INET;
	use IO::Select;
	my @CL = (); #: array of sock.Handles to Clients
	my $S; #: Socket-Server
	my $H; #: for IO::Select

	sub new { #: new Socket-Server
		my $me = {};
		$me->{'a'} = shift; #: loc.Adddress address
		$me->{'p'} = shift; #: port to connect
		$S = IO::Socket::INET->new(
				LocalAddr => $me->{'a'},
				LocalPort => $me->{'p'},
				Proto     => 'tcp',
				Listen    => 1,
				Reuse     => 1,
				Timeout   => 60
				);
			die "Can't create SoServ ($!)\n\n" unless $S;
		$H = IO::Select->new();
		$H->add($S);
		return bless $me;
	}

	#: wait for new connections
	sub waitNewConn { 
		my $me = shift;
		#: either endless (1) or just 2 clients (0):
		my $withKids = shift; 
		while (1) { # endless Loop if with Kids!
			# wait timeout-sec and then try again:
			my $newCL = $S->accept() || next; 
			print $newCL "Hi, guy, nice meeting you\n";
			$H->add($newCL);
			#update @CL instead of:push @CL,$newCL;
 			@CL = $H->can_write(1); 
			# no kid: return after 2 conn.
			return @CL if (@CL == 2 && !$withKids); 
		} # while (1)
	} # sub

	sub clients { return @CL }


#######   end packages   #############

package main;

	my $addr = 'localhost'; # hard coded for now
	my $port = 2345;        # dito
	my $Serv = SoServ::new( $addr,$port ); # start Server

# Array of Handles to Clients derived from SoServ->@CL
	my @Clients = (); 

	my $withKids = 1; # want kids or everyth. in 1 process?

	if ($withKids) {
		spawn($Serv); # kid is waiting for new Clients
	} else {
		# no kid, waiting here for new (2) Clients
		@Clients = $Serv->waitNewConn(0); 
	}

	my $line = '';
	my $f = '/home/cas/Data/sp1Min/spAdj.dta';
	my $n = 9; # just 9 lines for now
	open(SP, "< $f") or die "can't open SP: $f: $!"; #

	while (defined($line = <SP>)) {
		print $line; # control
		@Clients = $Serv->clients() if ($withKids);
		for (@Clients) {
			print $_ $line;
		}
		last if (!$n--);
	}
	close(SP);
exit;

	sub spawn {
		my $S = shift;
		my $pid;
		if (!defined($pid = fork)) {
			print "cannot fork: $!";
			return;
		} elsif ($pid) {
			print " I'm the Server-Parent: pid:$pid \$\$:$$\n";
			return; # I'm the parent
		}
		$S->waitNewConn(1); # yes with Kids, of course => (1)
		exit;
	} # end sub spawn