Listing 5. server2way.pl

#!/usr/bin/perl -w
# server2way.pl - a server that reads from
# and writes to a client
use strict;
use IO::Socket;
use Sys::Hostname;
my $sock = new IO::Socket::INET(
                   LocalHost => 'localhost',
                   LocalPort => 7890,
                   Proto     => 'tcp',
                   Listen    => SOMAXCONN,
                   Reuse     => 1);
$sock or die "no socket :$!";
STDOUT->autoflush(1);
my($new_sock, $buf);
while ($new_sock = $sock->accept()) {
    # got a client connection, so read
    # line by line until end-of-file
    while (defined($buf = <$new_sock>)) {
	# respond to client request using
	# a cleverly disguised switch
        # statement
	foreach ($buf) {
            /^HELLO$/ and 
                 print($new_sock "Hi\n"), 
                 last;
            /^NAME$/  and 
                 print($new_sock hostname(),
                       "\n"), 
                 last;
	    /^DATE$/  and 
                 print($new_sock  
                       scalar(localtime),
                       "\n"), 
                 last;
	    # default case:
	    print $new_sock "DEFAULT\n";
	}
    }
    close $new_sock;
}