On Friday, 14 March 2025 02:16:56 Pacific Daylight Time Frederick Virchanza
Gotham via Std-Proposals wrote:
> But nowadays, whenever I need a UUID for anything, I just generate a
> 128-Bit random number. I don't manually set the 6 bits to indicate that
> it's version 4. And I think that's what everyone else is doing now too.

No, most people who call it "UUID" do set the proper bits. Even some that
don't call it that, like systemd's ID128, do it too.

$ uuidgen; uuidgen; uuidgen; uuidgen
3cc591d7-a753-4bab-831c-4ed78d717f77
ba58a3ff-f408-4062-9250-320d1483ca11
bcc625ab-8c22-487f-90fe-cf923db77e60
58b71d64-1609-4b3c-a659-105dc9556876

$ cat /proc/sys/kernel/random/{uuid,uuid,uuid,uuid}
0d6c4bf1-7bc2-4450-b656-b967614e92e4
1ba7b93f-e220-4a61-a8ce-b571aaf3732f
8193f264-5874-4e42-aa98-a53d4bf81da9
4e7a800c-225b-4bef-8673-e6efb83b970c

$ systemd-id128 new -u; systemd-id128 new -u; systemd-id128 new -u; systemd-
id128 new -u
d127bde2-b75a-49bd-8ffa-fb4b9288845e
b63dffa7-079d-49ed-bf72-f1edcaa0907d
c63ae9b4-e952-40bf-bd34-dc6c7382e92c
3e61f3a9-a24f-43dd-b8fc-5a5e066b9d40

You can see the "4" in the third group and that the fourth group's first digit
is >= 8.

-- 
Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org
  Principal Engineer - Intel DCAI Platform & System Engineering