NAME
    NetAddr::IP - Manages IPv4 addresses and subnets

SYNOPSIS
      use NetAddr::IP;

      my $ip = new NetAddr::IP 'loopback';

      print "The address is ", $ip->addr, " with mask ", $ip->mask, "\n" ;

      if ($ip->within(new NetAddr::IP "127.0.0.0", "255.0.0.0")) {
          print "Is a loopback address\n";
      }

                                    # This prints 127.0.0.1/32
      print "You can also say $ip...\n";

DESCRIPTION
    This module provides a number of methods useful for handling IPv4
    addresses ans subnets. Hopefully, its methods are also usable for IPv6
    addresses.

    Methods so far include:

    `->new([$addr, [ $mask ]])'
        This method creates a new IPv4 address with the supplied address in
        `$addr' and an optional netmask `$mask', which can be omitted to get
        a /32 mask.

        `$addr' can be almost anything that can be resolved to an IP address
        in all the notations I have seen over time. It can optionally
        contain the mask in CIDR notation.

        If called with no arguments, 'default' is assumed.

    `->broadcast()'
        Returns a new object refering to the broadcast address of a given
        subnet.

    `->network()'
        Returns a new object refering to the network address of a given
        subnet.

    `->addr()'
        Returns a scalar with the address part of the object as a
        dotted-quad.

    `->mask()'
        Returns a scalar with the mask as a dotted-quad.

    `->masklen()'
        Returns a scalar the number of one bits in the mask.

    `->cidr()'
        Returns a scalar with the address and mask in CIDR notation.

    `->numeric()'
        When called in a scalar context, will return a numeric
        representation of the address part of the IP address. When called in
        an array contest, it returns a list of two elements. The first
        element is as described, the second element is the numeric
        representation of the netmask.

    `$me->contains($other)'
        Returns true when `$me' completely contains `$other'. False is
        returned otherwise and `undef' is returned if `$me' and `$other' are
        of different versions.

    `$me->within($other)'
        The complement of `->contains()'. Returns true when `$me' is
        completely con tained within `$other'.

    `->split($bits)'
        Returns a list of objects, representing subnets of `$bits' mask
        produced by splitting the original object, which is left unchanged.
        Note that `$bits' must be longer than the original object's mask in
        order for it to be splittable.

        Note that `$bits' can be given as an integer (the length of the
        mask) or as a dotted-quad. If omitted, a host mask is assumed.

    `->splitref($bits)'
        A (faster) version of `->split()' that returns a reference to a list
        of objects instead of a real list. This is useful when large numbers
        of objects are expected.

    `->hostenum()'
        Returns the list of hosts within a subnet.

    `->hostenumref()'
        Faster version of `->hostenum()', returning a reference to a list.

    `$me->compact($addr1, $addr2, ...)'
        Given a list of objects (including `$me'), this method will compact
        all the addresses and subnets into the largest (ie, least specific)
        subnets possible that contain exactly all of the given objects.

        Note that in versions prior to 3.02, if fed with the same IP subnets
        multiple times, these subnets would be returned. From 3.02 on, a
        more "correct" approach has been adopted and only one address would
        be returned.

    `$me->compactref(\@list)'
        As usual, a faster version of =item `->compact()' that returns a
        reference to a list. Note that this method takes a reference to a
        list instead.

    `->first()'
        Returns a new object representing the first useable IP address
        within the subnet (ie, the first host address).

    `->last()'
        Returns a new object representing the last useable IP address within
        the subnet (ie, one less than the broadcast address).

    `->num()'
        Returns the number of useable addresses IP addresses within the
        subnet, not counting the broadcast address.

    In addition to the methods, some functions are overloaded to ease
    manipulation of the objects. The available operations are:

    Stringification
        An object can be used just as a string. For instance, the following
        code

                my $ip = new NetAddr::IP 'loopback';
                print "$ip\n";

        Will print the string 127.0.0.1/8.

    Equality
        You can test for equality with either `eq' or `=='.

    Dereferencing as an ARRAY
        You can do something along the lines of

                my $net = new NetAddr::IP $cidr_spec;
                for my $ip (@$net) {
                  print "Host $ip is in $net\n";
                }

        However, note that this might generate a very large amount of items
        in the list. You must be careful when doing this kind of expansion.

  EXPORT

    None by default.

HISTORY
    0.01
        *   original version; Basic testing and release to CPAN as version
            0.01. This is considered beta software.

    0.02
        *   Multiple changes to fix endiannes issues. This code is now
            moderately tested on Wintel and Sun/Solaris boxes.

    0.03
        *   Added ->first and ->last methods. Version changed to 0.03.

    1.00
        *   Implemented ->new_subnet. Version changed to 1.00.

        *   less croak()ing when improper input is fed to the module. A more
            consistent 'undef' is returned now instead to allow the user to
            better handle the error.

    1.10
        *   As per Marnix A. Van Ammers [mav6@ns02.comp.pge.com] suggestion,
            changed the syntax of the loop in host_enum to be the same of
            the enum method.

        *   Fixed the MS-DOS ^M at the end-of-line problem. This should make
            the module easier to use for *nix users.

    1.20
        *   Implemented ->compact and ->expand methods.

        *   Applying for official name

    1.21
        *   Added ->addr_number and ->mask_bits. Currently we return normal
            numbers (not BigInts). Please test this in your platform and
            report any problems!

    2.00
        *   Released under the new *official* name of NetAddr::IP

    2.10
        *   Added support for ->new($min, $max, $bits) form

        *   Added ->to_numeric. This helps serializing objects

    2.20
        *   Chris Dowling reported that the sort method introduced in v1.20
            for ->expand and ->compact doesn't always return a number under
            perl versions < 5.6.0. His fix was applied and redistributed.
            Thanks Chris!

        *   This module is hopefully released with no CR-LF issues!

        *   Fixed a warning about uninitialized values during make test

    2.21
        *   Dennis Boylan pointed out a bug under Linux and perhaps other
            platforms as well causing the error "Sort subroutine didn't
            return single value at
            /usr/lib/perl5/site_perl/5.6.0/NetAddr/IP.pm line 299, <> line
            2." or similar. This was fixed.

    2.22
        *   Some changes suggested by Jeroen Ruigrok and Anton Berezin were
            included. Thanks guys!

    2.23
        *   Bug fix for /XXX.XXX.XXX.XXX netmasks under v5.6.1 suggested by
            Tim Wuyts. Thanks!

        *   Tested the module under MACHTYPE=hppa1.0-hp-hpux11.00. It is now
            konwn to work under Linux (Intel/AMD), Digital Unix (Alpha),
            Solaris (Sun), HP-UX11 (HP-PA-RISC), Windows 9x/NT/2K (using
            ActiveState on Intel).

    2.24
        *   A spurious warning when expand()ing with -w under certain
            circumstances was removed. This involved using /31s, /32s and
            the same netmask as the input. Thanks to Elie Rosenblum for
            pointing it out.

        *   Slight change in license terms to ease redistribution as a
            Debian package.

    3.00
            This is a major rewrite, supposed to fix a number of issues
            pointed out in earlier versions.

            The goals for this version include getting rid of BigInts,
            speeding up and also cleaning up the code, which is written in a
            modular enough way so as to allow IPv6 functionality in the
            future, taking benefit from most of the methods.

            Note that no effort has been made to remain backwards compatible
            with earlier versions. In particular, certain semantics of the
            earlier versions have been removed in favor of faster
            performance.

            This version was tested under Win98/2K (ActiveState
            5.6.0/5.6.1), HP-UX11 on PA-RISC (5.6.0), RedHat Linux 6.2
            (5.6.0), Digital Unix on Alpha (5.6.0), Solaris on Sparc (5.6.0)
            and possibly others.

    3.01
        *   Added `->numeric()'.

        *   `->new()' called with no parameters creates a default
            NetAddr::IP object.

    3.02
        *   Fxed `->compact()' for cases of equal subnets or
            mutually-contained IP addresses as pointed out by Peter Wirdemo.
            Note that now only distinct IP addresses will be returned by
            this method.

        *   Fixed the docs as suggested by Thomas Linden.

        *   Introduced overloading to ease certain common operations.

        *
                Fixed compatibility issue with C<-E<gt>num()> on 64-bit processors.

AUTHOR
    Luis E. Munoz <lem@cantv.net>

WARRANTY
    This software comes with the same warranty as perl itself (ie, none), so
    by using it you accept any and all the liability.

LICENSE
    This software is (c) Luis E. Munoz. It can be used under the terms of
    the perl artistic license provided that proper credit for the work of
    the author is preserved in the form of this copyright notice and license
    for this module.

SEE ALSO
    perl(1).