libuuid
uuid-generate
uuid-generate/  random
uuid-generate/  time
8.1

libuuid

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)

"aaf20848-cdd2-4077-a44c-dba8f51a"

> (uuid-generate)

"bfd53598-087a-420b-b5c1-f6680e4f"

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)

"aa0ed163-f109-4c1c-a641-8def499a"

> (uuid-generate/random)

"f138981a-2702-4b99-bc88-0e329946"

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)

"eaf3959e-ae15-11eb-a31f-679c34e6"

> (uuid-generate/time)

"eaf3a7c8-ae15-11eb-a31f-679c34e6"