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UUIDD(8)		      System Administration			UUIDD(8)

NAME
     uuidd - UUID generation daemon

SYNOPSIS
     uuidd [options]

DESCRIPTION
     The uuidd daemon is used by the UUID library to generate universally unique
     identifiers  (UUIDs),  especially time-based UUIDs, in a secure and guaran-
     teed-unique fashion, even in the face of large numbers of	threads  running
     on different CPUs trying to grab UUIDs.

OPTIONS
     -C, --cont-clock[=time]
	 Activate  continuous  clock  handling for time based UUIDs. uuidd could
	 use all possible clock values, beginning with the daemon's start  time.
	 The optional argument can be used to set a value for the max_clock_off-
	 set.  This  guarantees,  that	a  clock  value of a UUID will always be
	 within the range of the max_clock_offset.

	 The option -C or  --cont-clock  enables  the  feature	with  a  default
	 max_clock_offset of 2 hours.

	 The  option  -C<NUM>[hd]  or --cont-clock=<NUM>[hd] enables the feature
	 with a max_clock_offset of NUM seconds. In case of an appended h or  d,
	 the  NUM  value  is read in hours or days. The minimum value is 60 sec-
	 onds, the maximum value is 365 days.

     -d, --debug
	 Run uuidd in debugging mode. This prevents uuidd from running as a dae-
	 mon.

     -F, --no-fork
	 Do not daemonize using a double-fork.

     -k, --kill
	 If currently a uuidd daemon is running, kill it.

     -n, --uuids number
	 When issuing a test request to a running uuidd, request a bulk response
	 of number UUIDs.

     -P, --no-pid
	 Do not create a pid file.

     -p, --pid path
	 Specify the pathname where the pid file should be written. By	default,
	 the pid file is written to {runstatedir}/uuidd/uuidd.pid.

     -q, --quiet
	 Suppress some failure messages.

     -r, --random
	 Test  uuidd  by trying to connect to a running uuidd daemon and request
	 it to return a random-based UUID.

     -S, --socket-activation
	 Do not create a socket but instead expect it  to  be  provided  by  the
	 calling  process.  This  implies --no-fork and --no-pid. This option is
	 intended to be used only with systemd(1). It needs to be enabled with a
	 configure option.

     -s, --socket path
	 Make uuidd use this pathname for the unix-domain  socket.  By	default,
	 the  pathname	used is {runstatedir}/uuidd/request. This option is pri-
	 marily for debugging purposes, since the pathname is hard-coded in  the
	 libuuid library.

     -T, --timeout number
	 Make uuidd exit after number seconds of inactivity.

     -t, --time
	 Test  uuidd  by trying to connect to a running uuidd daemon and request
	 it to return a time-based UUID.

     -h, --help
	 Display help text and exit.

     -V, --version
	 Display version and exit.

EXAMPLE
     Start up a daemon, print 42 random keys, and then stop the daemon:

	 uuidd -p /tmp/uuidd.pid -s /tmp/uuidd.socket
	 uuidd -d -r -n 42 -s /tmp/uuidd.socket
	 uuidd -d -k -s /tmp/uuidd.socket

AUTHOR
     The uuidd daemon was written by Theodore Ts'o <tytso@mit.edu>.

SEE ALSO
     uuid(3), uuidgen(1)

REPORTING BUGS
     For       bug	 reports,	use	  the	    issue	 tracker
     <https://github.com/util-linux/util-linux/issues>.

AVAILABILITY
     The uuidd command is part of the util-linux package which can be downloaded
     from		   Linux		  Kernel		 Archive
     <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.41.1		   2025-06-24				UUIDD(8)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=uuidd&sektion=8&manpath=FreeBSD+Ports+15.1.quarterly>

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