# phpman > man > uuidd(8)

[UUIDD(8)](https://www.chedong.com/phpMan.php/man/UUIDD/8/markdown)                                System Administration                               [UUIDD(8)](https://www.chedong.com/phpMan.php/man/UUIDD/8/markdown)



## 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
           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
           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)](https://www.chedong.com/phpMan.php/man/systemd/1/markdown).
           It needs to be enabled with a configure option.

### -s --socket
           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
           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 Theodore Ts’o <<tytso@mit.edu>>.

## SEE ALSO
       [**uuid**(3)](https://www.chedong.com/phpMan.php/man/uuid/3/markdown), [**uuidgen**(1)](https://www.chedong.com/phpMan.php/man/uuidgen/1/markdown)

## 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/>>.



util-linux 2.37.2                            2021-06-02                                     [UUIDD(8)](https://www.chedong.com/phpMan.php/man/UUIDD/8/markdown)