8.12
libuuid
Jan Dvorak <mordae@anilinux.org>
Interface to the libuuid library usable to generate high-quality UUIDs.
| (require libuuid) | package: libuuid |
procedure
(uuid-generate) → string?
Generate new universally unique identifier using /dev/urandom,
if available. If it is not available, use current time, local ethernet
MAC address and random data from a pseudo-random generator.
Examples:
> (uuid-generate) "d85f295d-d40e-4b53-b62b-c46a0c30"
> (uuid-generate) "56b19935-7013-4980-9dee-fd89cc03"
procedure
When /dev/urandom is available, same as uuid-generate,
but fails back to a pseudo-random generator only.
Can be used to prevent any chance of host’s MAC address leaking, at the cost of slightly higher chance of generating non-unique identifiers if the worst-case situation arises on multiple hosts.
Examples:
> (uuid-generate/random) "bc6703ad-d3a7-4dc9-b482-2a5227ed"
> (uuid-generate/random) "dc92e182-56b3-41d5-9ab6-7dd9f91f"
procedure
Same as uuid-generate when the /dev/urandom is missing.
Could potentially produce non-uniqueue identifiers if used concurrently so if you do not absolutely need sequential identifiers, stick with the generic (and safe) uuid-generate function above.
Examples:
> (uuid-generate/time) "0b45880e-c577-11ee-b686-e94920d7"
> (uuid-generate/time) "0b45a2f8-c577-11ee-b686-e94920d7"