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)
"826f5893-81a2-4d42-adbe-97a96de6357a"
> (uuid-generate)
"8626b0a1-a76c-4635-8c35-caed16360512"

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)
"2fa15259-4bd3-4fb0-a401-6dc9ba6e23a2"
> (uuid-generate/random)
"fe8f1a07-bd06-44a9-ae2d-194fdf535615"

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)
"c5d9fe16-815a-11f0-9845-7727c6b9a837"
> (uuid-generate/time)
"c5da240e-815a-11f0-9845-7727c6b9a837"