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)
"0b3736e1-b70f-42a2-a39f-b065fa95b2fa"
> (uuid-generate)
"c6905a06-460f-48f1-9286-a3b5a7cefd07"

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)
"83cd4ed3-8019-4011-960f-a838b0775748"
> (uuid-generate/random)
"f7cefb09-ebce-417c-9fb0-aa4e6b9ae052"

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)
"85cc4334-ca4c-11f0-af7b-15d73df9c636"
> (uuid-generate/time)
"85cc5946-ca4c-11f0-af7b-15d73df9c636"