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 guaranteed-unique fashion, even in the face of large numbers of threads running on different CPUs trying to grab UUIDs.

OPTIONS¶

-d, --debug

Run uuidd in debugging mode. This prevents uuidd from running as a daemon.

-h, --help

Display help screen and exit.

-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, --pid path

Specify the pathname where the pid file should be written. By default, the pid file is written to /var/uuidd/uuidd.pid.

-P, --no-pid

Do not create pid file.

-F, --no-fork

Do not daemonize using double-fork.

-S, --socket-activation

Do not create the socket and instead expect it to be provided by the calling process. Implies --no-fork and --no-pid. As of this writing, this option is supposed to be used only with systemd. This option must be enabled with a configure option.

-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 path

Specify the pathname used for the unix-domain socket used by uuidd. By default, the pathname used is /var/uuidd/request. This is primarily for debugging purposes, since the pathname is hard-coded in the libuuid library.

-T, --timeout timeout

Specify a timeout for uuidd. If specified, then uuidd will exit after timeout 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.

-V, --version

Output version information 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>.

AVAILABILITY¶

The uuidd daemon is part of the util-linux package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux/.

SEE ALSO¶

uuid(3), uuidgen(1)