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)
"ef7c524a-bde2-40c3-bb76-9ef802917e71"
> (uuid-generate)
"919bc7c9-ea0c-423f-a5b5-83f10935cc12"

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)
"e6eb8972-5667-42ff-a804-907bce6be431"
> (uuid-generate/random)
"5be1eb82-9a23-4f41-a303-51661dd9dfbf"

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)
"fd3ace72-6bd8-11f0-b9bc-1bc47c1681a9"
> (uuid-generate/time)
"fd3af302-6bd8-11f0-b9bc-1bc47c1681a9"