IO::Socket::INET(3perl) | Perl Programmers Reference Guide | IO::Socket::INET(3perl) |
IO::Socket::INET - Object interface for AF_INET domain sockets
use IO::Socket::INET;
"IO::Socket::INET" provides an object interface to creating and using sockets in the AF_INET domain. It is built upon the IO::Socket interface and inherits all the methods defined by IO::Socket.
In addition to the key-value pairs accepted by IO::Socket, "IO::Socket::INET" provides.
PeerAddr Remote host address <hostname>[:<port>] PeerHost Synonym for PeerAddr PeerPort Remote port or service <service>[(<no>)] | <no> LocalAddr Local host bind address hostname[:port] LocalHost Synonym for LocalAddr LocalPort Local host bind port <service>[(<no>)] | <no> Proto Protocol name (or number) "tcp" | "udp" | ... Type Socket type SOCK_STREAM | SOCK_DGRAM | ... Listen Queue size for listen ReuseAddr Set SO_REUSEADDR before binding Reuse Set SO_REUSEADDR before binding (deprecated, prefer ReuseAddr) ReusePort Set SO_REUSEPORT before binding Broadcast Set SO_BROADCAST before binding Timeout Timeout value for various operations MultiHomed Try all addresses for multi-homed hosts Blocking Determine if connection will be blocking mode
If "Listen" is defined then a listen socket is created, else if the socket type, which is derived from the protocol, is SOCK_STREAM then connect() is called. If the "Listen" argument is given, but false, the queue size will be set to 5.
Although it is not illegal, the use of "MultiHomed" on a socket which is in non-blocking mode is of little use. This is because the first connect will never fail with a timeout as the connect call will not block.
The "PeerAddr" can be a hostname or the IP-address on the "xx.xx.xx.xx" form. The "PeerPort" can be a number or a symbolic service name. The service name might be followed by a number in parenthesis which is used if the service is not known by the system. The "PeerPort" specification can also be embedded in the "PeerAddr" by preceding it with a ":".
If "Proto" is not given and you specify a symbolic "PeerPort" port, then the constructor will try to derive "Proto" from the service name. As a last resort "Proto" "tcp" is assumed. The "Type" parameter will be deduced from "Proto" if not specified.
If the constructor is only passed a single argument, it is assumed to be a "PeerAddr" specification.
If "Blocking" is set to 0, the connection will be in nonblocking mode. If not specified it defaults to 1 (blocking mode).
Examples:
$sock = IO::Socket::INET->new(PeerAddr => 'www.perl.org', PeerPort => 'http(80)', Proto => 'tcp'); $sock = IO::Socket::INET->new(PeerAddr => 'localhost:smtp(25)'); $sock = IO::Socket::INET->new(Listen => 5, LocalAddr => 'localhost', LocalPort => 9000, Proto => 'tcp'); $sock = IO::Socket::INET->new('127.0.0.1:25'); $sock = IO::Socket::INET->new( PeerPort => 9999, PeerAddr => inet_ntoa(INADDR_BROADCAST), Proto => 'udp', LocalAddr => 'localhost', Broadcast => 1 ) or die "Can't bind : $IO::Socket::errstr\n";
If the constructor fails it will return "undef" and set the $IO::Socket::errstr package variable to contain an error message.
$sock = IO::Socket::INET->new(...) or die "Cannot create socket - $IO::Socket::errstr\n";
For legacy reasons the error message is also set into the global $@ variable, and you may still find older code which looks here instead.
$sock = IO::Socket::INET->new(...) or die "Cannot create socket - $@\n";
Socket, IO::Socket
Graham Barr. Currently maintained by the Perl Porters. Please report all bugs at <https://github.com/Perl/perl5/issues>.
Copyright (c) 1996-8 Graham Barr <gbarr@pobox.com>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
2023-11-25 | perl v5.36.0 |