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)
"166d5132-4769-4bdc-b881-d9968f9b5ad2"
> (uuid-generate)
"807feb71-98c3-4bc4-b227-4492bb41a46c"

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)
"4e853f72-8189-47f1-85b4-99929e08735d"
> (uuid-generate/random)
"be6f76ad-909b-4a88-97e8-d01aa5026888"

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)
"060dbfbc-dedb-11f0-acd9-6715f54c7ca1"
> (uuid-generate/time)
"060dd600-dedb-11f0-acd9-6715f54c7ca1"