You want to connect to a socket on a remote machine.
This solution assumes you're using the Internet to communicate. For TCP-like communication within a single machine, see Recipe 17.6 .
use IO::Socket; $socket = IO::Socket::INET->new(PeerAddr => $remote_host, PeerPort => $remote_port, Proto => "tcp", Type => SOCK_STREAM) or die "Couldn't connect to $remote_host:$remote_port : $@\n"; # ... do something with the socket print $socket "Why don't you call me anymore?\n"; $answer = <$socket>; # and terminate the connection when we're done close($socket);
or create a socket by hand for better control:
use Socket; # create a socket socket(TO_SERVER, PF_INET, SOCK_STREAM, getprotobyname('tcp')); # build the address of the remote machine $internet_addr = inet_aton($remote_host) or die "Couldn't convert $remote_host into an Internet address: $!\n"; $paddr = sockaddr_in($remote_port, $internet_addr); # connect connect(TO_SERVER, $paddr) or die "Couldn't connect to $remote_host:$remote_port : $!\n"; # ... do something with the socket print TO_SERVER "Why don't you call me anymore?\n"; # and terminate the connection when we're done close(TO_SERVER);
While coding this by hand requires a lot of steps, the IO::Socket::INET class wraps them all in a convenient constructor. The important things to know are where you're going (the PeerAddr and PeerPort parameters) and how you're getting there (the Type parameter). IO::Socket::INET tries to determine these things from what you've given it. It deduces Proto from the Type and Port if possible, and assumes
PeerAddr is a string containing either a hostname (
If you want a SOCK_STREAM connection to a port on a particular machine with no other options, pass a single string to
$client = IO::Socket::INET->new("www.yahoo.com:80") or die $@;
If an error occurs, IO::Socket::INET will return
$s = IO::Socket::INET->new(PeerAddr => "Does not Exist", Peerport => 80, Type => SOCK_STREAM ) or die $@;
If your packets are disappearing into a network void, it can take a while for your inability to connect to a port to be recognized. You can decrease this time by specifying a
$s = IO::Socket::INET->new(PeerAddr => "bad.host.com", PeerPort => 80, Type => SOCK_STREAM, Timeout => 5 ) or die $@;
If you do this, though, there's no way to tell from
INADDR_ANY is a special address, meaning "listen on any interface." If you want to restrict it to a particular IP address, add a
$inet_addr = inet_aton("220.127.116.11"); $paddr = sockaddr_in($port, $inet_addr); bind(SOCKET, $paddr) or die "bind: $!";
If you know only the name, do this:
Copyright © 2002 O'Reilly & Associates. All rights reserved.