libuuid🔗ℹ

Interface to the libuuid library usable to generate high-quality UUIDs.

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)
"cde8e6ec-ed70-49cf-b2fa-986cd3cb5f46"
> (uuid-generate)
"55330031-24f8-48da-9273-fbdfec6090a1"

procedure
(uuid-generate/random) → string?

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)
"4baf634c-8579-4f73-af5c-26466bd4ea19"
> (uuid-generate/random)
"d2d58f51-9c0a-4c02-80d7-cdd22d08fd6d"

procedure
(uuid-generate/time) → string?

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)
"513c3c86-c81d-11f0-82a8-ef133793686c"
> (uuid-generate/time)
"513c42c6-c81d-11f0-82a8-ef133793686c"