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, and some tweakable parameters.
❤️🐧
Yeah but please don’t actually use this. Use a proper UUID library that works cross-platform and lets you choose the UUID type and can be seeded etc.
This is awesome. Thank you
I’ve used this in some bash scripts, very useful!
That’s what you get when you define a file system as “a system that names things”.
boot_idseems to be static, probably set at boot.
So don’t use it for a random uuid.Thank you so much for sharing this!
Works in Termux on Android
See also: /dev/null
It’s basically a black hole where you can throw anything.
Yes, but what if it were a subscription? May I present: /dev/null-as-a-Service.
cat /proc/sys/kernel/random/uuid | /dev/nullWould have to be
cat /proc/sys/kernel/random/uuid > /dev/nullYou can’t pipe to a file, only to programs, and since /dev/null isn’t an executable your command will simply give an error.
To make it more clear, consider using
dd, which lets you explicitly specify an input and output file. For example:dd if=/proc/sys/kernel/random/uuid of=/dev/sda1wait shit that wasn’t the right output oh god oh fui saw this and came to do THE THING but you beat me too it. GOOD ANYA
That reminds me of the CPU stress test I ran many years ago.
dd if=/dev/random of=/dev/nullIf you have 8 cores, just open 8 terminals, and run that code in each of them.
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/dev/urandom should stress the CPU more. /dev/random can be entropy limited
The information will be evenly distributed upon its surface and some believe one day it will be be radiated back out into the rest of the system.
That’s a horrifying concept. Better not think about it.
no.
