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)
"4e30d8f6-e7de-44b9-bc77-8094de9d0535"
> (uuid-generate)
"0f7fd830-06c1-44f5-80df-48fad62cd124"

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)
"6d7cbd09-3fe2-4ec4-97db-42477bbf7cae"
> (uuid-generate/random)
"cc581f44-45d6-49ed-9bc1-a07e42bbd367"

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)
"6433a088-5741-11f0-93fd-bd585527adec"
> (uuid-generate/time)
"6433c400-5741-11f0-93fd-bd585527adec"