1.\" Copyright (c) 2002 Marcel Moolenaar 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.\" 27.Dd May 23, 2002 28.Dt UUIDGEN 1 29.Os 30.Sh NAME 31.Nm uuidgen 32.Nd generate universally unique identifiers 33.Sh SYNOPSIS 34.Nm 35.Op Fl 1 36.Op Fl n Ar count 37.Op Fl o Ar filename 38.Sh DESCRIPTION 39The 40.Nm 41utility by default generates a single universally unique identifier (UUID), 42also known as a globally unique identifier (GUID). 43The UUID is written to stdout by default. 44The following options can be used to change the behaviour of 45.Nm : 46.Bl -tag -width indent 47.It Fl 1 48This option only has effect if multiple identifiers are to be generated and 49instructs 50.Nm 51to not generate them in batch, but one at a time. 52.It Fl n 53This option controls the number of identifiers generated. 54By default, multiple 55identifiers are generated in batch. 56.It Fl o 57Redirect output to 58.Ar filename 59instead of stdout. 60.El 61.Pp 62Batched generation yields a dense set of identifiers in such a way that there 63is no identifier that is larger than the smallest identifier in the set and 64smaller than the largest identifier in the set and that is not already in the 65set. 66.Pp 67When generating the identifiers one at a time, the identifiers will be close 68to each other, but operating system latency and processing time will be 69reflected in the distance between two successive identifiers. 70.Sh DIAGNOSTICS 71.Ex -std 72.Sh SEE ALSO 73.Xr uuidgen 2 , 74.Xr uuid 3 75.Sh HISTORY 76The 77.Nm 78command first appeared in 79.Fx 5.0 . 80