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MaxMind::DB::Reader(3pm) User Contributed Perl Documentation MaxMind::DB::Reader(3pm)


MaxMind::DB::Reader - Read MaxMind DB files and look up IP addresses


version 1.000014


    my $reader = MaxMind::DB::Reader->new( file => 'path/to/database.mmdb' );
    my $record = $reader->record_for_address('');


This module provides a low-level interface to the MaxMind DB file format <>.

If you are looking for an interface to MaxMind's GeoIP2 or GeoLite2 downloadable databases <>, you should also check out the GeoIP2 distribution. That distribution provides a higher level OO interface to those databases.

This API will work with any MaxMind DB databases, regardless of whether it is a GeoIP2 database or not. In addition, if speed is critical, this API will always be faster than the GeoIP2 modules, since it returns results as a raw Perl data structure rather than as an object.


The MaxMind-DB-Reader distribution ships with a single pure Perl implementation of the Reader API. There is a separate distribution on CPAN, MaxMind::DB::Reader::XS, that provides an XS implementation which links against libmaxminddb <>.

The XS implementation is approximately 100 times faster than the pure Perl implementation, so if speed is important to you, we highly recommend that you install it!

If you install the XS implementation it will be automatically loaded. You do not need to change your code to take advantage of it.


This module provides the following API:

MaxMind::DB::Reader->new( file => $path )

This method returns a new reader object. Note that the class of the object returned will actually be either MaxMind::DB::Reader::PP or MaxMind::DB::Reader::XS.

If you need to check that an object is a valid reader, you should check that the object does the "MaxMind::DB::Reader::Role::Reader" role.

The "file" parameter is a required attribute for the constructor. It must be a string containing a path to a file. The constructor will die if the file provided is not readable.

You can also pass an additional parameter, "data_source", which must be a valid filehandle. This is useful in testing. For example, you can have the reader read from a filehandle opened to a scalar reference. Under normal usage, the reader simply opens the provided file to read from.


This method takes an IPv4 or IPv6 address as a string. This can be either a dotted quad ( or any valid IPv6 format ("abcd::1234", "::", etc.).

This method will die if the address is not a valid IP address.

The method returns the data associated with the IP address. Depending on the contents of the database, this can be a scalar or a reference to an array or hash.

$reader->iterate_search_tree( $data_callback, $node_callback )

This method iterates over the entire search tree, calling the callbacks you provided for each data record and node in the tree.

Both callbacks are optional (although calling this with neither will do a lot of work for no good reason).

The node callback is called for every node in the database's search tree. This callback is called with three arguments. These are the node's number (which is based on its position in the file) and the values of its left and right records. These values are themselves numbers. See the MaxMind DB spec <> for more details on what node record values mean.

The data callback is called for records that point to the database's data section. The first two arguments identify the network that the data record applies to. The first argument is an IP address as an integer and the second is a network mask length. The final argument is the data associated with the network.


This method returns a MaxMind::DB::Metadata object for the database.


This method returns the file path passed to the constructor.


This module uses semantic versioning as described by <>. Version numbers can be read as X.YYYZZZ, where X is the major number, YYY is the minor number, and ZZZ is the patch number.


This module is deprecated and will only receive fixes for major bugs and security vulnerabilities. New features and functionality will not be added.

Please report all issues with this code using the GitHub issue tracker at <>.

Bugs may be submitted through <>.


  • Dave Rolsky <>
  • Olaf Alders <>


  • Greg Oschwald <>
  • Mark Fowler <>
  • Mateu X Hunter <>
  • Ran Eilam <>
  • William Stevenson <>
  • Will Storey <>


This software is Copyright (c) 2019 by MaxMind, Inc.

This is free software, licensed under:

  The Artistic License 2.0 (GPL Compatible)
2019-12-22 perl v5.30.0