8. System administration commands (usually only for root)

UUIDD

Section: System Administration (8)
Updated: 2021-06-02
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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.

-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 primarily 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.

-V, --version

: Output version information and exit.

-h, --help

: Display help screen 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

REPORTING BUGS

For bug reports, use the issue tracker at <https://github.com/karelzak/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/>.

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