 @@ -1,14 +1,14 @@
-.\" $NetBSD: uuidgen.2,v 1.4 2005/01/30 18:13:04 jwise Exp $
+.\" $NetBSD: uuidgen.2,v 1.5 2019/07/24 06:11:57 riastradh Exp $
 .\" $FreeBSD: src/lib/libc/sys/uuidgen.2,v 1.7 2003/06/27 13:41:29 yar Exp $
 .\" Copyright (c) 2002 Marcel Moolenaar
 .\" All rights reserved.
 .\"
 .\" Redistribution and use in source and binary forms, with or without
 .\" modification, are permitted provided that the following conditions
 .\" are met:
 .\"
 .\" 1. Redistributions of source code must retain the above copyright
 .\"    notice, this list of conditions and the following disclaimer.
 .\" 2. Redistributions in binary form must reproduce the above copyright
 .\"    notice, this list of conditions and the following disclaimer in the
 .\"    documentation and/or other materials provided with the distribution.
 @@ -37,47 +37,34 @@
 .Sh SYNOPSIS
 .In sys/types.h
 .In sys/uuid.h
 .Ft int
 .Fn uuidgen "struct uuid *store" "int count"
 .Sh DESCRIPTION
 The
 .Fn uuidgen
 system call generates
 .Fa count
 universally unique identifiers (UUIDs) and writes them to the buffer
 pointed to by
 .Fa store .
-The identifiers are generated according to the syntax and semantics of the
+The identifiers are randomly generated according to UUID version 4.
 DCE version 1 variant of universally unique identifiers.
 See below for a more in-depth description of the identifiers.
 When no IEEE 802
 address is available for the node field, a random multi-cast address is
 generated for each invocation of the system call.
 According to the algorithm of generating time-based UUIDs, this will also
 force a new random clock sequence, thereby increasing the likelihood for
 the identifier to be unique.
 .Pp
 When multiple identifiers are to be generated, the
 .Fn uuidgen
 system call will generate a set of identifiers that is dense 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
 Universally unique identifiers, also known as globally unique identifiers
 (GUIDs), have a binary representation of 128-bits.
-The grouping and meaning of these bits is described by the following
+The grouping and meaning of these bits is based on historical methods
-structure and its description of the fields that follow it:
+of generation from on timestamps and IEEE 802 MAC addresses, and is
 described by the following structure and its description of the fields
 that follow it:
 .Bd -literal
 struct uuid {
 	uint32_t	time_low;
 	uint16_t	time_mid;
 	uint16_t	time_hi_and_version;
 	uint8_t		clock_seq_hi_and_reserved;
 	uint8_t		clock_seq_low;
 	uint8_t		node[_UUID_NODE_LEN];
 };
 .Ed
 .Bl -tag -width ".Va clock_seq_hi_and_reserved"
 .It Va time_low
 The least significant 32 bits of a 60-bit timestamp.
 @@ -122,26 +109,39 @@ system call can fail with:
 .Bl -tag -width Er
 .It Bq Er EFAULT
 The buffer pointed to by
 .Fa store
 could not be written to for any or all identifiers.
 .It Bq Er EINVAL
 The
 .Fa count
 argument is less than 1 or larger than the hard upper limit of 2048.
 .El
 .Sh SEE ALSO
 .Xr uuidgen 1 ,
 .Xr uuid 3
 .Rs
 .%A P. Leach
 .%A M. Mealling
 .%A R. Salz
 .%T A Universally Unique IDentifier (UUID) URN Namespace
 .%R RFC 4122
 .%I IETF
 .%D July 2005
 .Re
 .Sh STANDARDS
-The identifiers are represented and generated in conformance with the DCE 1.1
+The identifiers are represented and generated in conformance with IETF
-RPC specification.
+RFC 4122, based on the historic DCE 1.1 RPC specification of the Open
 Software Foundation (now the Open Group).
 The
 .Fn uuidgen
 system call is itself not part of the specification.
 .Sh HISTORY
 The
 .Fn uuidgen
 system call first appeared in
 .Fx 5.0
 and was subsequently added to
 .Nx 2.0 .
 It was changed to use version 4 UUIDs, i.e. randomly generated UUIDs,
 in
 .Nx 8.0 .