sd_id128_randomize(3) — Linux manual page

SD_ID128_RANDOMIZE(3)      sd_id128_randomize      SD_ID128_RANDOMIZE(3)

NAME

       sd_id128_randomize - Generate 128-bit IDs

SYNOPSIS

       #include <systemd/sd-id128.h>

       int sd_id128_randomize(sd_id128_t *ret);

DESCRIPTION

       sd_id128_randomize() generates a new randomized 128-bit ID and
       returns it in ret. Every invocation returns a new randomly
       generated ID. This uses the getrandom(2) kernel random number
       generator.

       Note that sd_id128_randomize() always returns a UUID Variant 1
       Version 4 compatible ID. It is hence guaranteed that this
       function will never return the ID consisting of all zero or all
       one bits (SD_ID128_NULL, SD_ID128_ALLF).

       For more information about the "sd_id128_t" type, see
       sd-id128(3).

       systemd-id128(1)'s new command may be used as a command line
       front-end for sd_id128_randomize().

RETURN VALUE

       The call returns 0 on success (in which case ret is filled in),
       or a negative errno-style error code.

NOTES

       Functions described here are available as a shared library, which
       can be compiled against and linked to with the
       libsystemd pkg-config(1) file.

       The code described here uses getenv(3), which is declared to be
       not multi-thread-safe. This means that the code calling the
       functions described here must not call setenv(3) from a parallel
       thread. It is recommended to only do calls to setenv() from an
       early phase of the program when no other threads have been
       started.

HISTORY

       sd_id128_randomize() was added in version 187.

SEE ALSO

       systemd(1), sd-id128(3), machine-id(5), getrandom(2), random(4),
       sd_id128_get_machine(3)

COLOPHON

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       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://github.com/systemd/systemd.git⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
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systemd 257~devel                                  SD_ID128_RANDOMIZE(3)

Pages that refer to this page: sd_bus_set_server(3), sd-id128(3), sd_id128_get_machine(3), systemd.directives(7), systemd.index(7)

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