type-o-serve.pl

#!/usr/bin/perl -w

use Socket;
use Carp;
use FileHandle;

# (1) use port 8080 by default, unless overridden on command line
$port = (@ARGV ? $ARGV[0] : 8080);

# (2) create local TCP socket and set it to listen for connections
$proto = getprotobyname('tcp');
socket(S, PF_INET, SOCK_STREAM, $proto) || die;
setsockopt(S, SOL_SOCKET, SO_REUSEADDR, pack("l", 1)) || die;
bind(S, sockaddr_in($port, INADDR_ANY)) || die;
listen(S, SOMAXCONN) || die;

# (3) print a startup message
printf("    <<<Type-O-Serve Accepting on Port %d>>>\n\n",$port);

while (1)
{
    # (4) wait for a connection C
    $cport_caddr = accept(C, S);
    ($cport,$caddr) = sockaddr_in($cport_caddr);
    C->autoflush(1);

    # (5) print who the connection is from
    $cname = gethostbyaddr($caddr,AF_INET);
    printf("    <<<Request From '%s'>>>\n",$cname);

    # (6) read request msg until blank line, and print on screen
    while ($line = <C>)
    {
		print $line;
		if ($line =~ /^\r/) { last; }
    }

    # (7) prompt for response message, and input response lines,
    #     sending response lines to client, until solitary "."
    printf("    <<<Type Response Followed by '.'>>>\n");

    while ($line = <STDIN>)
    {
		$line =~ s/\r//;
		$line =~ s/\n//;
		if ($line =~ /^\./) { last; }
		print C $line . "\r\n";
    }

    close(C);
}