Data::Range::Compare::Stream::Cookbook::COMPARE_IPV4 - IPV4 Howto for Data::Range::Compare::Stream
This section covers how to create a compare class that can handle ipv4 ranges.
One thing to keep in mind when dealing with IPV4 data: There are alot of valid formats! With that in mind the internals of Data::Range::Compare::Stream process integers, wich for the most part will handle just about everything we need wth 2 exceptions.
These 2 examples work with integers but do not work with IPV4 address ranges
Less than 0:
0/0 -1
Greater than 0xffffffff:
255.255.255.255/32 + 1
The solution is to add add some sanity checking into our Range class
Data::Range::Compare::Stream handles integers, but not notations and processing integers is always faster than converting strings on the fly.
The solution is to add a parser interface into our base class.
Example package
package Data::Range::Compare::Stream::IPV4; use strict; use warnings; use Data::IPV4::Range::Parse qw(auto_parse_ipv4_range int_to_ip ALL_BITS); use base qw(Data::Range::Compare::Stream); use constant NEW_FROM_CLASS=>'Data::Range::Compare::Stream::IPV4'; # our sanity checking consists of 2 parts # 1. overloading the bool operator # 2. creating our boolean function # Sanity check 1 # overloading the default bool operator and defining our boolean function use overload bool=>\&boolean, fallback=>1 ; # Sanity check 2 sub boolean { my ($self)=@_; return -4 unless defined($self->range_start); return -3 unless defined($self->range_end); return -2 if $self->cmp_values($self->range_start,$self->range_end)==1; return -1 if $self->cmp_values($self->range_end,ALL_BITS)==1; return 0 if $self->cmp_values(0,$self->range_start)==1; 1; } sub parse_range { my ($class,@args)=@_; my ($start,$end)= auto_parse_ipv4_range(@args); print $class->NEW_FROM_CLASS,"\n"; return $class->NEW_FROM_CLASS->new($start,$end); } sub range_start_to_string () { my ($self)=@_; return int_to_ip($self->range_start); } sub range_end_to_string () { my ($self)=@_; return int_to_ip($self->range_end); } 1;
Now we can use the new Compare package to handle processing our IPV4 Ranges
use strict; use warnings; use Data::IPV4::Range::Parse qw(ALL_BITS); use Data::Range::Compare::Stream::IPV4; # parse and check a valid range my $range_a=Data::Range::Compare::Stream::IPV4->parse_range('0/0'); if($range_a) { print "yes [$range_a] is valid\n"; } # parse and check an invalid cidr my $range_b=Data::Range::Compare::Stream::IPV4->parse_range('0/'); unless($range_b) { print "no range_b is not valid!\n"; } # build a new valid instance from integers my $range_c=new Data::Range::Compare::Stream::IPV4(0,11); if($range_c) { print "yes [$range_c] is valid\n"; } # build an new range with the start value as invalid my $range_d=new Data::Range::Compare::Stream::IPV4(-1,11); unless($range_d) { print "No range_d is no valid\n"; } # build an new range with the end value as invalid my $range_e=new Data::Range::Compare::Stream::IPV4(0,(ALL_BITS + 1)); unless($range_e) { print "No range_e is no valid\n"; }
Michael Shipper
As of version 0.001 the Project has been moved to Source-Forge.net
Data Range Compare https://sourceforge.net/projects/data-range-comp/
Copyright 2011 Michael Shipper. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Data::Range::Compare::Stream, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Data::Range::Compare::Stream
CPAN shell
perl -MCPAN -e shell install Data::Range::Compare::Stream
For more information on module installation, please visit the detailed CPAN module installation guide.