NAME

       Data::UUID - Globally/Universally Unique Identifiers (GUIDs/UUIDs)

SEE INSTEAD?

       The module Data::GUID provides another interface for generating GUIDs.  Right now, it
       relies on Data::UUID, but it may not in the future.  Its interface may be just a little
       more straightforward for the average Perl programer.

SYNOPSIS

         use Data::UUID;

         $ug    = Data::UUID->new;
         $uuid1 = $ug->create();
         $uuid2 = $ug->create_from_name(<namespace>, <name>);

         $res   = $ug->compare($uuid1, $uuid2);

         $str   = $ug->to_string( $uuid );
         $uuid  = $ug->from_string( $str );

DESCRIPTION

       This module provides a framework for generating v3 UUIDs (Universally Unique Identifiers,
       also known as GUIDs (Globally Unique Identifiers). A UUID is 128 bits long, and is
       guaranteed to be different from all other UUIDs/GUIDs generated until 3400 CE.

       UUIDs were originally used in the Network Computing System (NCS) and later in the Open
       Software Foundation's (OSF) Distributed Computing Environment.  Currently many different
       technologies rely on UUIDs to provide unique identity for various software components.
       Microsoft COM/DCOM for instance, uses GUIDs very extensively to uniquely identify classes,
       applications and components across network-connected systems.

       The algorithm for UUID generation, used by this extension, is described in the Internet
       Draft "UUIDs and GUIDs" by Paul J. Leach and Rich Salz.  (See RFC 4122.)  It provides
       reasonably efficient and reliable framework for generating UUIDs and supports fairly high
       allocation rates -- 10 million per second per machine -- and therefore is suitable for
       identifying both extremely short-lived and very persistent objects on a given system as
       well as across the network.

       This modules provides several methods to create a UUID.  In all methods, "<namespace>" is
       a UUID and "<name>" is a free form string.

          # creates binary (16 byte long binary value) UUID.
          $ug->create();
          $ug->create_bin();

          # creates binary (16-byte long binary value) UUID based on particular
          # namespace and name string.
          $ug->create_from_name(<namespace>, <name>);
          $ug->create_from_name_bin(<namespace>, <name>);

          # creates UUID string, using conventional UUID string format,
          # such as: 4162F712-1DD2-11B2-B17E-C09EFE1DC403
          $ug->create_str();
          $ug->create_from_name_str(<namespace>, <name>);

          # creates UUID string as a hex string,
          # such as: 0x4162F7121DD211B2B17EC09EFE1DC403
          $ug->create_hex();
          $ug->create_from_name_hex(<namespace>, <name>);

          # creates UUID string as a Base64-encoded string
          $ug->create_b64();
          $ug->create_from_name_b64(<namespace>, <name>);

          Binary UUIDs can be converted to printable strings using following methods:

          # convert to conventional string representation
          $ug->to_string(<uuid>);

          # convert to hex string
          $ug->to_hexstring(<uuid>);

          # convert to Base64-encoded string
          $ug->to_b64string(<uuid>);

          Conversly, string UUIDs can be converted back to binary form:

          # recreate binary UUID from string
          $ug->from_string(<uuid>);
          $ug->from_hexstring(<uuid>);

          # recreate binary UUID from Base64-encoded string
          $ug->from_b64string(<uuid>);

          Finally, two binary UUIDs can be compared using the following method:

          # returns -1, 0 or 1 depending on whether uuid1 less
          # than, equals to, or greater than uuid2
          $ug->compare(<uuid1>, <uuid2>);

       Examples:

          use Data::UUID;

          # this creates a new UUID in string form, based on the standard namespace
          # UUID NameSpace_URL and name "www.mycompany.com"

          $ug = Data::UUID->new;
          print $ug->create_from_name_str(NameSpace_URL, "www.mycompany.com");

   EXPORT
       The module allows exporting of several standard namespace UUIDs:

       NameSpace_DNS
       NameSpace_URL
       NameSpace_OID
       NameSpace_X500

AUTHOR

       Alexander Golomshtok <agolomsh@cpan.org>

SEE ALSO

       The Internet Draft "UUIDs and GUIDs" by Paul J. Leach and Rich Salz (RFC 4122)