DragonFly On-Line Manual Pages

Search: Section:  


UUIDGEN(1)	       DragonFly General Commands Manual	    UUIDGEN(1)

NAME

uuidgen -- generate universally unique identifiers

SYNOPSIS

uuidgen [-1] [-n count] [-o filename]

DESCRIPTION

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.

EXIT STATUS

The uuidgen utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

uuidgen(2), uuid(3)

HISTORY

The uuidgen command first appeared in FreeBSD 5.0. DragonFly 5.3 September 7, 2005 DragonFly 5.3 UUIDGEN(1) UUIDGEN(1)

NAME

uuidgen - command-line utility to create a new UUID value

SYNOPSIS

uuidgen [ -r | -t ]

DESCRIPTION

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 options.

OPTIONS

-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 /dev/random. -t Generate a time-based UUID. This method creates a UUID based on the system clock plus the system's ethernet hardware address, if present.

CONFORMING TO

OSF DCE 1.1

AUTHOR

uuidgen was written by Andreas Dilger for libuuid.

AVAILABILITY

uuidgen is part of libuuid from the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net.

SEE ALSO

libuuid(3) E2fsprogs version 1.42.13 May 2015 UUIDGEN(1)

Search: Section: