trusty (3) sd_id128_get_machine.3.gz

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 an 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 shared library, which can
       be compiled and linked to with the libsystemd-id128pkg-config(1) file.

SEE ALSO

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