libuuid
uuid-generate
uuid-generate/  random
uuid-generate/  time
8.18.0.10

libuuid🔗ℹ

Jan Dvorak <mordae@anilinux.org>

Interface to the libuuid library usable to generate high-quality UUIDs.

 (require libuuid) 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)

"777b7386-1060-4167-9922-99a7ba364795"

> (uuid-generate)

"b9822388-52af-4f30-8425-40434aa4a729"

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)

"207fff60-f55a-4f36-9367-791f9073deea"

> (uuid-generate/random)

"cafb0ed5-f269-44f3-89e5-8ccaa5331a96"

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)

"b2a751cc-704d-11f0-bfef-c1609b205601"

> (uuid-generate/time)

"b2a758b6-704d-11f0-bfef-c1609b205601"