libuuid

8.17.0.1

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)
"c15a87ec-139f-4232-99fa-7a439d52f40e"
> (uuid-generate)
"a3f9080d-e5a5-42d7-bacd-01ee610a0fda"

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)
"34231555-2312-4d82-b380-301f50bfed8f"
> (uuid-generate/random)
"7206271f-0d6f-41ba-b72d-390da9f39207"

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)
"c80fca08-2bba-11f0-b3e1-fb709d39d180"
> (uuid-generate/time)
"c80ff294-2bba-11f0-b3e1-fb709d39d180"