IPv4Addr(3)						User Contributed Perl Documentation					       IPv4Addr(3)

NAME

       Net::IPv4Addr - Perl extension for manipulating IPv4 addresses.

SYNOPSIS

	 use Net::IPv4Addr qw( :all );

	 my ($ip,$cidr) = ipv4_parse( "127.0.0.1/24" );
	 my ($ip,$cidr) = ipv4_parse( "192.168.100.10 / 255.255.255.0" );

	 my ($net,$msk) = ipv4_network( "192.168.100.30" );

	 my $broadcast	= ipv4_broadcast( "192.168.100.30/26" );

	 if ( ipv4_in_network( "192.168.100.0", $her_ip ) ) {
	   print "Welcome !";
	 }

	 etc.

DESCRIPTION

       Net::IPv4Addr provides functions for parsing IPv4 addresses both in traditional address/netmask format and in the new CIDR format.  There
       are also methods for calculating the network and broadcast address and also to see check if a given address is in a specific network.

ADDRESSES

       All of Net::IPv4Addr functions accepts addresses in many format. The parsing is very liberal.

       All these addresses would be accepted:

	   127.0.0.1
	   192.168.001.010/24
	   192.168.10.10/255.255.255.0
	   192.168.30.10 / 21
	   10.0.0.0 / 255.0.0.0
	   255.255.0.0

       Those wouldn't though:

	   272.135.234.0
	   192.168/16

       Most functions accepts the address and netmask or masklength in the same scalar value or as separate values. That is either

	   my($ip,$masklength) = ipv4_parse($cidr_str);
	   my($ip,$masklength) = ipv4_parse($ip_str,$msk_str);

USING

       No functions are exported by default. Either use the ":all" tag to import them all or explicitly import those you need.

FUNCTIONS

       ipv4_parse
	       my ($ip,$msklen) = ipv4_parse($cidr_str);
	       my $cidr = ipv4_parse($ip_str,$msk_str);
	       my ($ip) = ipv4_parse($ip_str,$msk_str);

	   Parse an IPv4 address and in scalar context the address in CIDR format and in an array context the address and the mask length.

	   If the parameters doesn't contains a netmask or a mask length, in scalar context only the IPv4 address is returned and in an array
	   context the mask length is undefined.

	   If the function cannot parse its input, it croaks. Trap it using "eval" if don't like that.

       ipv4_network
	       my $cidr = ipv4_network($ip_str);
	       my $cidr = ipv4_network($cidr_str);
	       my ($net,$msk) = ipv4_network( $net_str, $msk_str);

	   In scalar context, this function returns the network in CIDR format in which the address is. In array context, it returns the network
	   address and its mask length as a two elements array. If the input is an host without a netmask of mask length, the default netmask is
	   assumed.

	   Again, the function croak if the input is invalid.

       ipv4_broadcast
	       my ($broadcast) = ipv4_broadcast($ip_str);
	       my $broadcast   = ipv4_broadcast($ip_str,$msk_str);

	   This function returns the broadcast address. If the input doesn't contains a netmask or mask length, the default netmask is assumed.

	   This function croaks if the input is invalid.

       ipv4_network
	       my $cidr = ipv4_network($net_str);
	       my $cidr = ipv4_network($cidr_sstr);
	       my ($net,$msk) = ipv4_network( $ip_str, $mask_str);

	   In scalar context, this function returns the network in CIDR format in which the address is. In array context, it returns the network
	   address and its mask length as a two elements array. If the input is an host without a netmask or mask length, the default netmask is
	   assumed.

	   Again, the function croak if the input is invalid.

       ipv4_in_network
	       print "Yes" if ipv4_in_network( $cidr_str1, $cidr_str2);
	       print "Yes" if ipv4_in_network( $ip_str1, $mask_str1, $cidr_str2 );
	       print "Yes" if ipv4_in_network( $ip1, $mask1, $ip2, $msk2 );

	   This function checks if the second network is contained in the first one and it implements the following semantics :

	      If net1 or net2 is a magic address (0.0.0.0 or 255.255.255.255)
	      than this function returns true.

	      If net1 is an host, net2 will be in the same net only if
	      it is the same host.

	      If net2 is an host, it will be contained in net1 only if
	      it is part of net1.

	      If net2 is only part of net1 if it is entirely contained in
	      net1.

	   Trap bad input with "eval" or else.

       ipv4_checkip
	       if ($ip = ipv4_checkip($str) ) {
		   # Do something
	       }

	   Return the IPv4 address in the string or undef if the input doesn't contains a valid IPv4 address.

       ipv4_cidr2msk
	       my $netmask = ipv4_cidr2msk( $cidr );

	   Returns the netmask corresponding to the mask length given in input.  As usual, croaks if it doesn't like your input (in this case a
	   number between 0 and 32).

       ipv4_msk2cidr
	       my $masklen = ipv4_msk2cidr( $msk );

	   Returns the mask length of the netmask in input. As usual, croaks if it doesn't like your input.

AUTHOR

       Francis J. Lacoste <francis.lacoste@iNsu.COM>

COPYRIGHT

       Copyright (c) 1999, 2000 iNsu Innovations Inc.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the terms as perl itself.

SEE ALSO

       perl(1) ipv4calc(1).

perl v5.12.1							    2000-08-01							       IPv4Addr(3)