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.\" $FreeBSD: head/bin/uuidgen/uuidgen.1 235842 2012-05-23 16:19:19Z wblock $
.\"
.Dd May 23, 2012
.Dt UUIDGEN 1
.Os
.Sh NAME
.Nm uuidgen
.Nd generate universally unique identifiers
.Sh SYNOPSIS
.Nm
.Op Fl 1
.Op Fl n Ar count
.Op Fl o Ar filename
.Sh DESCRIPTION
The
.Nm
utility by default generates a single DCE version 1
universally unique identifier (UUID),
also known as a globally unique identifier (GUID).
The UUID is written to stdout by default.
The following options can be used to change the behaviour of
.Nm :
.Bl -tag -width indent
.It Fl 1
This option only has effect if multiple identifiers are to be generated and
instructs
.Nm
to not generate them in batch, but one at a time.
.It Fl n
This option controls the number of identifiers generated.
By default, multiple identifiers are generated in batch.
The upper hard limit is 2048
.Po see
.Xr uuidgen 2
.Pc .
.It Fl o
Redirect output to
.Ar filename
instead of stdout.
.El
.Pp
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.
.Pp
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.
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr uuidgen 2 ,
.Xr uuid 3
.Sh HISTORY
The
.Nm
command first appeared in
.Fx 5.0 .