.\" This file may be copied under the terms of the GNU Public License.
.\"
.\" Created Wed Mar 10 17:42:12 1999, Andreas Dilger
-.TH UUIDGEN "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
+.TH UUIDGEN 1 "@E2FSPROGS_MONTH@ @E2FSPROGS_YEAR@" "E2fsprogs version @E2FSPROGS_VERSION@"
.SH NAME
-uuidgen \- command\-line utility to create a new unique UUID value
+uuidgen \- command\-line utility to create a new UUID value
.SH SYNOPSIS
-.nf
-.B uuidgen
-.fi
+.B uuidgen
+[
+.B \-r
+|
+.B \-t
+]
.SH DESCRIPTION
The
.B uuidgen
-program creates a new universally unique identifier using the
-.BR libuuid "(3) functions " uuid_generate "(3) and " uuid_unparse "(3)."
-The new UUID can reasonably be considered unique among all UUIDs created
-on the local system, and among UUIDs created on other systems in the past
+program creates (and prints)
+a new universally unique identifier (UUID) using the
+.BR libuuid (3)
+library. The new UUID can reasonably 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.
-.SH RETURN VALUE
-The UUID of the form 1b4e28ba\-2fa1\-11d2\-883f\-b9a761bde3fb (in
-.BR printf (3)
-format "%08x\-%04x\-%04x\-%04x\-%012x") is output to the standard output.
+.PP
+There are two types of UUID's which
+.B uuidgen
+can generate: time-based UUID's and random-based UUID's. By
+default
+.B 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
+.B \-r
+or
+.B \-t
+options.
+.SH OPTIONS
+.TP
+.B \-r
+Generate a random-based UUID. This method creates a UUID consisting mostly
+of random bits. It requires that the operating system have a high
+quality random number generator, such as
+.IR /dev/random .
+.TP
+.B \-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.
.SH "CONFORMING TO"
OSF DCE 1.1
.SH AUTHOR
was written by Andreas Dilger for libuuid.
.SH AVAILABILITY
.B uuidgen
-is part of libuuid from the e2fsprogs package and is available for anonymous
-ftp from tsx\-11.mit.edu (and its mirrors) in /pub/linux/packages/ext2fs.
+is part of libuuid from the e2fsprogs package and is available from
+http://e2fsprogs.sourceforge.net.
.SH "SEE ALSO"
.BR libuuid (3)