DragonFly On-Line Manual Pages
UUIDGEN(1) DragonFly General Commands Manual UUIDGEN(1)
uuidgen -- generate universally unique identifiers
uuidgen [-1] [-n count] [-o filename]
The uuidgen utility by default generates a single DCE version 1 univer-
sally unique identifier (UUID), also known as a globally unique identi-
fier (GUID). The UUID is written to stdout by default. The following
options can be used to change the behaviour of uuidgen:
-1 This option only has effect if multiple identifiers are to be
generated and instructs uuidgen to not generate them in batch,
but one at a time.
-n This option controls the number of identifiers generated. By
default, multiple identifiers are generated in batch.
-o Redirect output to filename instead of stdout.
Batched generation yields a dense set of identifiers in such a way that
there is no identifier that is larger than the smallest identifier in the
set and smaller than the largest identifier in the set and that is not
already in the set.
When generating the identifiers one at a time, the identifiers will be
close to each other, but operating system latency and processing time
will be reflected in the distance between two successive identifiers.
The uuidgen utility exits 0 on success, and >0 if an error occurs.
The uuidgen command first appeared in FreeBSD 5.0.
DragonFly 5.3 September 7, 2005 DragonFly 5.3
uuidgen - command-line utility to create a new UUID value
uuidgen [ -r | -t ]
The uuidgen program creates (and prints) a new universally unique iden-
tifier (UUID) using the libuuid(3) library. The new UUID can reason-
ably be considered unique among all UUIDs created on the local system,
and among UUIDs created on other systems in the past and in the future.
There are two types of UUID's which uuidgen can generate: time-based
UUID's and random-based UUID's. By default uuidgen will generate a
random-based UUID if a high-quality random number generator is present.
Otherwise, it will chose a time-based UUID. It is possible to force
the generation of one of these two UUID types by using the -r or -t
-r Generate a random-based UUID. This method creates a UUID con-
sisting mostly of random bits. It requires that the operating
system have a high quality random number generator, such as
-t Generate a time-based UUID. This method creates a UUID based on
the system clock plus the system's ethernet hardware address, if
OSF DCE 1.1
uuidgen was written by Andreas Dilger for libuuid.
uuidgen is part of libuuid from the e2fsprogs package and is available
E2fsprogs version 1.42.13 May 2015 UUIDGEN(1)