NAME

       sd_id128_get_machine, sd_id128_get_boot - Retrieve 128-bit IDs

SYNOPSIS

       #include <systemd/sd-id128.h>

       int sd_id128_get_machine(sd_id128_t *ret);

       int sd_id128_get_boot(sd_id128_t *ret);

DESCRIPTION

       sd_id128_get_machine() returns the machine ID of the executing host. This reads and parses
       the machine-id(5) file. This function caches the machine ID internally to make retrieving
       the machine ID a cheap operation.

       sd_id128_get_boot() returns the boot ID of the executing kernel. This reads and parses the
       /proc/sys/kernel/random/boot_id file exposed by the kernel. It is randomly generated early
       at boot and is unique for every running kernel instance. See random(4) for more
       information. This function also internally caches the returned ID to make this call a
       cheap operation.

       Note that sd_id128_get_boot() always returns a UUID v4 compatible ID.
       sd_id128_get_machine() will also return a UUID v4-compatible ID on new installations but
       might not on older. It is possible to convert the machine ID into a UUID v4-compatible
       one. For more information, see machine-id(5).

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

RETURN VALUE

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

NOTES

       The sd_id128_get_machine() and sd_id128_get_boot() interfaces are available as a shared
       library, which can be compiled and linked to with the "libsystemd" pkg-config(1) file.

SEE ALSO

       systemd(1), sd-id128(3), machine-id(5), random(4), sd_id128_randomize(3)