Data::UUID::LibUUID(3pm)
NAME
Data::UUID::LibUUID - uuid.h based UUID generation (versions 2 and 4
depending on platform)
SYNOPSIS
use Data::UUID::LibUUID; my $uuid = new_uuid_string();
DESCRIPTION
This module provides bindings for libuuid shipped with e2fsprogs or
uuid-dev on debian, and also works with the system uuid.h on darwin.
EXPORTS
- new_uuid_string $version
new_uuid_binary $version - Returns a new UUID in string (dash separated hex) or binary (16
octets) format. - $version can be either 2, or 4 and defaults to whatever the
underlying implementation prefers. - Version 1 is timestamp/MAC based UUIDs, like Data::UUID provides.
They reveal time and host information, so they may be considered a security risk. - Version 2 is described here
<http://www.opengroup.org/onlinepubs/9696989899/chap5.htm#tagcjh_08_02_01_01>. It is similar to version 1 but considered more secure. - Version 4 is based just on random data. This is not guaranteed to
be high quality random data, but usually is supposed to be. - On MacOS X "getpid" is called before UUID generation, to ensure
UUIDs are unique accross forks. Behavior on other platforms may
vary. - uuid_to_binary $str_or_bin
- Converts a UUID from string or binary format to binary format.
- Returns undef on a non UUID argument.
- uuid_to_string $str_or_bin
- Converts a UUID from string or binary format to string format.
- Returns undef on a non UUID argument.
- uuid_eq $str_or_bin, $str_or_bin
- Checks if two UUIDs are equivalent. Returns true if they are, or
false if they aren't. - Returns undef on non UUID arguments.
- uuid_compare $str_or_bin, $str_or_bin
- Returns -1, 0 or 1 depending on the lexicographical order of the
UUID. This works like the "cmp" builtin. - Returns undef on non UUID arguments.
- new_dce_uuid_string
new_dce_uuid_binary - These two subroutines are a little hackish in that they take no
arguments but also do not validate the arguments, so they can be
abused as methods:
package MyFoo;use Data::UUID::LibUUID (new_dce_uuid_string => { -as "generate_uuid" },);sub yadda {my $self = shift;
my $id = $self->generate_uuid;} - This allows the ID generation code to be subclassed, but still
keeps the hassle down to a minimum. DCE is UUID version two
specification. - ascending_ident
- Creates a lexically ascending identifier containing a UUID, high
resolution timestamp, and a counter. - This is not a UUID (it's longer), but if you can store variable
length identifier (and exposing the system clock is not an issue)
they can be used to create an identifier that is both universally
unique, and lexically increasing. - Note that while the identifiers are universally unique, there is no
universal ordering (that would require synchronization), so
identifiers generated on different machines or even different
process/thread could have IDs which interleave.
TODO
o Consider bundling libuuid for when no system "uuid.h" exists.
SEE ALSO
Data::GUID, Data::UUID, UUID, <http://e2fsprogs.sourceforge.net/>
VERSION CONTROL
This module is maintained using Darcs. You can get the latest version
from <http://nothingmuch.woobling.org/code>, and use "darcs send" to
commit changes.
AUTHOR
Yuval Kogman <nothingmuch@woobling.org>
COPYRIGHT
- Copyright (c) 2008 Yuval Kogman. All rights reserved
This program is free software; you can redistribute
it and/or modify it under the same terms as Perl itself.