libuuid
uuid-generate
uuid-generate/  random
uuid-generate/  time
9.2.0.5

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)

"4d07295d-950f-4755-9834-bd11703b0b5d"

> (uuid-generate)

"b3de6732-f451-4df1-b008-3fa8b511e828"

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)

"7fbb43ae-ad00-48c6-a3ca-dc4302f1a38d"

> (uuid-generate/random)

"bc57fd08-6f07-4b06-9a98-e2584d90aef3"

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)

"6654ea7c-6aa3-11f1-a558-2d9e91778e9f"

> (uuid-generate/time)

"66553bee-6aa3-11f1-a558-2d9e91778e9f"