.\" Copyright 1999 Andreas Dilger (adilger@enel.ucalgary.ca) .\" .\" This man page was created for libuuid.so.1.1 from e2fsprogs-1.14. .\" .\" 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 1 "September 2019" "E2fsprogs version 1.45.4" .SH NAME uuidgen \- command\-line utility to create a new UUID value .SH SYNOPSIS .B uuidgen [ .B \-r | .B \-t ] .SH DESCRIPTION The .B uuidgen 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. .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 .B uuidgen was written by Andreas Dilger for libuuid. .SH AVAILABILITY .B uuidgen is part of libuuid from the e2fsprogs package and is available from http://e2fsprogs.sourceforge.net. .SH "SEE ALSO" .BR libuuid (3)