NAME

       IO::Interface - Perl extension for access to network card configuration information

SYNOPSIS

        # ======================
        # the new, preferred API
        # ======================

        use IO::Interface::Simple;

        my $if1   = IO::Interface::Simple->new('eth0');
        my $if2   = IO::Interface::Simple->new_from_address('127.0.0.1');
        my $if3   = IO::Interface::Simple->new_from_index(1);

        my @interfaces = IO::Interface::Simple->interfaces;

        for my $if (@interfaces) {
           print "interface = $if\n";
           print "addr =      ",$if->address,"\n",
                 "broadcast = ",$if->broadcast,"\n",
                 "netmask =   ",$if->netmask,"\n",
                 "dstaddr =   ",$if->dstaddr,"\n",
                 "hwaddr =    ",$if->hwaddr,"\n",
                 "mtu =       ",$if->mtu,"\n",
                 "metric =    ",$if->metric,"\n",
                 "index =     ",$if->index,"\n";

           print "is running\n"     if $if->is_running;
           print "is broadcast\n"   if $if->is_broadcast;
           print "is p-to-p\n"      if $if->is_pt2pt;
           print "is loopback\n"    if $if->is_loopback;
           print "is promiscuous\n" if $if->is_promiscuous;
           print "is multicast\n"   if $if->is_multicast;
           print "is notrailers\n"  if $if->is_notrailers;
           print "is noarp\n"       if $if->is_noarp;
         }

         # ===========
         # the old API
         # ===========

         use IO::Socket;
         use IO::Interface qw(:flags);

         my $s = IO::Socket::INET->new(Proto => 'udp');
         my @interfaces = $s->if_list;

         for my $if (@interfaces) {
           print "interface = $if\n";
           my $flags = $s->if_flags($if);
           print "addr =      ",$s->if_addr($if),"\n",
                 "broadcast = ",$s->if_broadcast($if),"\n",
                 "netmask =   ",$s->if_netmask($if),"\n",
                 "dstaddr =   ",$s->if_dstaddr($if),"\n",
                 "hwaddr =    ",$s->if_hwaddr($if),"\n";

           print "is running\n"     if $flags & IFF_RUNNING;
           print "is broadcast\n"   if $flags & IFF_BROADCAST;
           print "is p-to-p\n"      if $flags & IFF_POINTOPOINT;
           print "is loopback\n"    if $flags & IFF_LOOPBACK;
           print "is promiscuous\n" if $flags & IFF_PROMISC;
           print "is multicast\n"   if $flags & IFF_MULTICAST;
           print "is notrailers\n"  if $flags & IFF_NOTRAILERS;
           print "is noarp\n"       if $flags & IFF_NOARP;
         }

         my $interface = $s->addr_to_interface('127.0.0.1');

DESCRIPTION

       IO::Interface adds methods to IO::Socket objects that allows them to be used to retrieve
       and change information about the network interfaces on your system.  In addition to the
       object-oriented access methods, you can use a function-oriented style.

       THIS API IS DEPRECATED. Please see IO::Interface::Simple for the preferred way to get and
       set interface configuration information.

   Creating a Socket to Access Interface Information
       You must create a socket before you can access interface information. The socket does not
       have to be connected to a remote site, or even used for communication.  The simplest
       procedure is to create a UDP protocol socket:

         my $s = IO::Socket::INET->new(Proto => 'udp');

       The various IO::Interface functions will now be available as methods on this socket.

   Methods
       @iflist = $s->if_list
           The if_list() method will return a list of active interface names, for example "eth0"
           or "tu0".  If no interfaces are configured and running, returns an empty list.

       $addr = $s->if_addr($ifname [,$newaddr])
           if_addr() gets or sets the interface address.  Call with the interface name to
           retrieve the address (in dotted decimal format).  Call with a new address to set the
           interface.  In the latter case, the routine will return a true value if the operation
           was successful.

             my $oldaddr = $s->if_addr('eth0');
             $s->if_addr('eth0','192.168.8.10') || die "couldn't set address: $!";

           Special case: the address of the pseudo-device "any" will return the IP address
           "0.0.0.0", which corresponds to the INADDR_ANY constant.

       $broadcast = $s->if_broadcast($ifname [,$newbroadcast]
           Get or set the interface broadcast address.  If the interface does not have a
           broadcast address, returns undef.

       $mask = $s->if_netmask($ifname [,$newmask])
           Get or set the interface netmask.

       $dstaddr = $s->if_dstaddr($ifname [,$newdest])
           Get or set the destination address for point-to-point interfaces.

       $hwaddr = $s->if_hwaddr($ifname [,$newhwaddr])
           Get or set the hardware address for the interface. Currently only ethernet addresses
           in the form "00:60:2D:2D:51:70" are accepted.

       $flags = $s->if_flags($ifname [,$newflags])
           Get or set the flags for the interface.  The flags are a bitmask formed from a series
           of constants.  See "Exportable constants" below.

       $ifname = $s->addr_to_interface($ifaddr)
           Given an interface address in dotted form, returns the name of the interface
           associated with it.  Special case: the INADDR_ANY address, 0.0.0.0 will return a
           pseudo-interface name of "any".

   EXPORT
       IO::Interface exports nothing by default.  However, you can import the following symbol
       groups into your namespace:

         :functions   Function-oriented interface (see below)
         :flags       Flag constants (see below)
         :all         All of the above

   Function-Oriented Interface
       By importing the ":functions" set, you can access IO::Interface in a function-oriented
       manner.  This imports all the methods described above into your namespace.  Example:

         use IO::Socket;
         use IO::Interface ':functions';

         my $sock = IO::Socket::INET->new(Proto=>'udp');
         my @interfaces = if_list($sock);
         print "address = ",if_addr($sock,$interfaces[0]);

   Exportable constants
       The ":flags" constant imports the following constants for use with the flags returned by
       if_flags():

         IFF_ALLMULTI
         IFF_AUTOMEDIA
         IFF_BROADCAST
         IFF_DEBUG
         IFF_LOOPBACK
         IFF_MASTER
         IFF_MULTICAST
         IFF_NOARP
         IFF_NOTRAILERS
         IFF_POINTOPOINT
         IFF_PORTSEL
         IFF_PROMISC
         IFF_RUNNING
         IFF_SLAVE
         IFF_UP

       This example determines whether interface 'tu0' supports multicasting:

         use IO::Socket;
         use IO::Interface ':flags';
         my $sock = IO::Socket::INET->new(Proto=>'udp');
         print "can multicast!\n" if $sock->if_flags & IFF_MULTICAST.

AUTHOR

       Lincoln Stein <lstein@cshl.org>

       This module is distributed under the same license as Perl itself.

SEE ALSO

       perl(1), IO::Socket(3), IO::Multicast(3), IO::Interface::Simple