sd_id128_randomize — Generate 128-bit IDs
#include <systemd/sd-id128.h>
int sd_id128_randomize( | sd_id128_t *ret) ; |
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()
.
The call returns 0 on success (in which case
ret
is filled in), or a negative
errno-style error code.
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.