Array::IntSpan::IP - a Module for arrays using IP addresses as indices
use Array::IntSpan::IP;
my $foo = Array::IntSpan::IP->new(['123.45.67.0', '123.45.67.255', 'Network 1'],
['123.45.68.0', '123.45.68.127', 'Network 2'],
['123.45.68.128', '123.45.68.255', 'Network 3']);
print "The address 123.45.68.37 is on network ".$foo->lookup("\173\105\150\45").".\n";
unless (defined($foo->lookup(((123*256+45)*256+65)*256+67))) {
print "The address 123.45.65.67 is not on a known network.\n";
}
print "The address 123.45.68.177 is on network ".$foo->lookup("123.45.68.177").".\n";
$foo->set_range('123.45.68.128', '123.45.68.255', 'Network 4');
print "The address 123.45.68.177 is now on network ".$foo->lookup("123.45.68.177").".\n";
Array::IntSpan::IP brings the advantages of Array::IntSpan to IP
address indices. Anywhere you use an index in Array::IntSpan, you
can use an IP address in one of three forms in Array::IntSpan::IP.
The three accepted forms are:
- Dotted decimal
-
This is the standard human-readable format for IP addresses. The
conversion checks that the octets are in the range 0-255. Example:
'123.45.67.89'.
- Network string
-
A four character string representing the octets in network
order. Example:
"\173\105\150\131".
- Integer
-
A integer value representing the IP address. Example:
((123*256+45)*256+67)*256+89 or 2066563929.
Note that the algorithm has no way of distinguishing between the
integer values 1000 through 9999 and the network string format. It
will presume network string format in these instances. For instance,
the integer 1234 (representing the address '0.0.4.210') will be
interpreted as "\61\62\63\64", or the IP address '49.50.51.52'.
This is unavoidable since Perl does not strongly type integers and
strings separately and there is no other information available to
distinguish between the two in this situation. I do not expect that
this will be a problem in most situations. Most users will probably
use dotted decimal or network string notations, and even if they do
use the integer notation the likelihood that they will be using the
addresses '0.0.3.232' through '0.0.39.15' as indices is
relatively low.
The class method Array::IntSpan::IP::ip_as_int takes as its one
parameter the IP address in one of the three formats mentioned above
and returns the integer notation.
Toby Everett, teverett@alascom.att.com
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