SD\_ID128\_RANDOMIZE(3) sd\_id128\_randomize SD\_ID128\_RANDOMIZE(3) .SH "NAME" sd\_id128\_randomize - Generate 128-bit IDs .SH "SYNOPSIS" ``` #include ``` .HP 552u **int sd\_id128\_randomize(sd\_id128\_t \*ret);** .SH "DESCRIPTION" .PP **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)](/man/os/systemd/getrandom.2) kernel random number generator. .PP 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**). .PP For more information about the sd\_id128\_t type, see [**sd-id128**(3)](/man/os/systemd/sd-id128.3). .PP [**systemd-id128**(1)](/man/os/systemd/systemd-id128.1)'s **new** command may be used as a command line front-end for **sd\_id128\_randomize()**. .SH "RETURN VALUE" .PP The call returns 0 on success (in which case *ret* is filled in), or a negative errno-style error code. .SH "NOTES" .PP Functions described here are available as a shared library, which can be compiled against and linked to with the **libsystemd** [**pkg-config**(1)](/man/os/systemd/pkg-config.1) file. .PP The code described here uses [**getenv**(3)](/man/os/systemd/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)](/man/os/systemd/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. .SH "HISTORY" .PP **sd\_id128\_randomize()** was added in version 187. .SH "SEE ALSO" .PP [**systemd**(1)](/man/os/systemd/systemd.1), [**sd-id128**(3)](/man/os/systemd/sd-id128.3), [**machine-id**(5)](/man/os/systemd/machine-id.5), [**getrandom**(2)](/man/os/systemd/getrandom.2), [**random**(4)](/man/os/systemd/random.4), [**sd\_id128\_get\_machine**(3)](/man/os/systemd/sd_id128_get_machine.3) systemd 262.2 --- Document: sd_id128_randomize(3) from systemd 262.2-r1 (Chainguard OS) Source: https://github.com/systemd/systemd