1UUIDD(8)                     System Administration                    UUIDD(8)
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NAME

6       uuidd - UUID generation daemon
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SYNOPSIS

9       uuidd [options]
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DESCRIPTION

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

18       -C, --cont-clock[=time]
19           Activate continuous clock handling for time based UUIDs. uuidd
20           could use all possible clock values, beginning with the daemon’s
21           start time. The optional argument can be used to set a value for
22           the max_clock_offset. This gurantees, that a clock value of a UUID
23           will always be within the range of the max_clock_offset.
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25           The option '-C' or '--cont-clock' enables the feature with a
26           default max_clock_offset of 2 hours.
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28           The option '-C<NUM>[hd]' or '--cont-clock=<NUM>[hd]' enables the
29           feature with a max_clock_offset of NUM seconds. In case of an
30           appended h or d, the NUM value is read in hours or days. The
31           minimum value is 60 seconds, the maximum value is 365 days.
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33       -d, --debug
34           Run uuidd in debugging mode. This prevents uuidd from running as a
35           daemon.
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37       -F, --no-fork
38           Do not daemonize using a double-fork.
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40       -k, --kill
41           If currently a uuidd daemon is running, kill it.
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43       -n, --uuids number
44           When issuing a test request to a running uuidd, request a bulk
45           response of number UUIDs.
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47       -P, --no-pid
48           Do not create a pid file.
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50       -p, --pid path
51           Specify the pathname where the pid file should be written. By
52           default, the pid file is written to {runstatedir}/uuidd/uuidd.pid.
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54       -q, --quiet
55           Suppress some failure messages.
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57       -r, --random
58           Test uuidd by trying to connect to a running uuidd daemon and
59           request it to return a random-based UUID.
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61       -S, --socket-activation
62           Do not create a socket but instead expect it to be provided by the
63           calling process. This implies --no-fork and --no-pid. This option
64           is intended to be used only with systemd(1). It needs to be enabled
65           with a configure option.
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67       -s, --socket path
68           Make uuidd use this pathname for the unix-domain socket. By
69           default, the pathname used is {runstatedir}/uuidd/request. This
70           option is primarily for debugging purposes, since the pathname is
71           hard-coded in the libuuid library.
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73       -T, --timeout number
74           Make uuidd exit after number seconds of inactivity.
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76       -t, --time
77           Test uuidd by trying to connect to a running uuidd daemon and
78           request it to return a time-based UUID.
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80       -h, --help
81           Display help text and exit.
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83       -V, --version
84           Print version and exit.
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EXAMPLE

87       Start up a daemon, print 42 random keys, and then stop the daemon:
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89           uuidd -p /tmp/uuidd.pid -s /tmp/uuidd.socket
90           uuidd -d -r -n 42 -s /tmp/uuidd.socket
91           uuidd -d -k -s /tmp/uuidd.socket
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AUTHOR

94       The uuidd daemon was written by Theodore Ts’o <tytso@mit.edu>.
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SEE ALSO

97       uuid(3), uuidgen(1)
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REPORTING BUGS

100       For bug reports, use the issue tracker at
101       https://github.com/util-linux/util-linux/issues.
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AVAILABILITY

104       The uuidd command is part of the util-linux package which can be
105       downloaded from Linux Kernel Archive
106       <https://www.kernel.org/pub/linux/utils/util-linux/>.
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110util-linux 2.39.2                 2023-08-17                          UUIDD(8)
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