UUID_GENERATE(3) uuid_generate, uuid_generate_random, uuid_generate_time, uuid_generate_time_safe - UUID #include void uuid_generate(uuid_t out); void uuid_generate_random(uuid_t out); void uuid_generate_time(uuid_t out); int uuid_generate_time_safe(uuid_t out); void uuid_generate_md5(uuid_t out, const uuid_t ns, const char *name, size_t len); void uuid_generate_sha1(uuid_t out, const uuid_t ns, const char *name, size_t len); uuid_generate() (UUID). UUID getrandom(2), /dev/urandom /dev/random, . , uuid_generate() , , MAC- ethernet ( ) . uuid_generate_random() UUID, ( ). , UUID. uuid_generate_time() , MAC- ethernet ( ). , UUID, MAC- ethernet, , UUID. , uuid_generate() , . UUID, , uuid ( ) / uuidd(8), ( ). , , UUID. UUID, uuid_generate_time_safe. uuid_generate_time_safe() uuid_generate_time(), , , (. ). UUID 16 (128 ), 3,4x10^38 ( 10^80 , ). UUID UUID, , UUID, . uuid_generate_md5() uuid_generate_sha1() () MD5 SHA1 UUID UUID, . UUID V3 V5 UUID RFC-4122 . UUID ', out. uuid_generate_time_safe() , UUID , -1 - . UUID, DCE 1.1 OSF UUID V3 V5 RFC-4122 . Theodore Y. Ts'o uuidgen(1), uuid(3), uuid_clear(3), uuid_compare(3), uuid_copy(3), uuid_is_null(3), uuid_parse(3), uuid_time(3), uuid_unparse(3), uuidd(8) libuuid util-linux, 2.15.1. Linux . util-linux 2.41 2025-03-29 UUID_GENERATE(3)