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cat /proc/sys/kernel/random/uuid [I ❤️ Linux] (feddit.org)

submitted 1 day ago* (last edited 7 hours ago) by A_norny_mousse@feddit.org to c/linux@programming.dev

33 comments fedilink hide all child comments

That's all. I just found this in a random script. Generates a random UUID every time it's called. I didn't know.

Of course I can also use uuidgen or pipe /dev/(u)random into something to get a random alphanumeric string - but this is built right into the kernel!

In /proc/sys/kernel/random/, there's also boot_id which ~~seems to do the same~~ is static, and some tweakable parameters.

❤️🐧

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[-] Hamartiogonic@sopuli.xyz 1 points 21 hours ago

That reminds me of the CPU stress test I ran many years ago.

dd if=/dev/random of=/dev/null

If you have 8 cores, just open 8 terminals, and run that code in each of them.

[-] victorz@lemmy.world 1 points 9 hours ago

Can you guarantee that each process will run on its own core?

[-] Hamartiogonic@sopuli.xyz 1 points 8 hours ago

Absolutely not, quite the opposite actually. However, the end result is close to 100% CPU load, which is good enough for some purposes. Let’s say you want to test the performance of your CPU cooler, or overclock stability, this should good enough. There are also dedicated tools for people with more advanced needs.

[-] YerbaYerba@lemm.ee 4 points 21 hours ago

/dev/urandom should stress the CPU more. /dev/random can be entropy limited

[-] lime@feddit.nu 2 points 20 hours ago* (last edited 20 hours ago)

for i in {1..n}  # where n == number of cores
do
  dd if=/dev/urandom of=/dev/null &
done

# to stop:
jobs -p | xargs kill

[-] Hamartiogonic@sopuli.xyz 1 points 8 hours ago

Oh yeah. This looks like a much better way to do it. My solution is pretty bare bones by comparison.

[-] lime@feddit.nu 1 points 8 hours ago

the advantage of yours is that you can actually see the performance number afterwards.

this post was submitted on 24 May 2025

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