nixCraft 🐧perfect function doesn’t exis- 👇
Fuchsiii~~~my Ryzen 7750X:
is_computer_on(); // 1
a cache corrupting i7 14700k:
is_computer_on(); // 153
pecet 🦒🇪🇺@nixCraft not really perfect if it has undefined behavior
André van Schoubroeck
Philippa Cowderoy@GromBeestje @nixCraft It's critically important to run this in a separate process to HCF()!
Gudroot@GromBeestje @nixCraft This should also cover the temperature inside a supernova, so we are safe on that side ;)
Sasha Akhavi@GromBeestje @nixCraft wish I’d had access to this before I had to read a whole book to find out https://mitpress.mit.edu/9780262539739/your-computer-is-on-fire/
Cat 🐈🥗 (D.Burch) 
a mercurial mess of random thoughts
Peter Mount@GromBeestje @nixCraft reminds me of the old "lp0 on fire" error in some older Unixes
lp0 on fire 
@peter, it's still there in (at least) current Linux.
On a status check, “lp0 on fire” (for appropriate values of 0) may be logged; on opening the device file, “lp0 printer error” will be logged instead given the same error condition. It's specific to an error condition reported via the 8255 status port.
Chris [list of emoji]This is a true masterwork of wrongness.
Okay, I just googled it and it's real. I don't know whether to be delighted or horrified.
Also (and sorry for the monologuing), I once witnessed a demo of the original dual-processor BeBox where the presenter showed how to turn off one or the other of the cores from the settings interface. He then turned off both of the cores, and it did exactly what you'd expect. While the computer rebooted, he segued on to how robust the filesystem was.
So, on reflection, this seems pretty on-brand for them.
talpa@suetanvil @GromBeestje @nixCraft I was kind of sad when I was told that they later on removed that feature from BeOS
@suetanvil @nixCraft I recall reading these function were there to test the performance of userland-kernel calls.
That makes sense. My idle speculation was that they were there as the entry points to the hardware or kernel equivalents of debugging printfs, FWIW.
theslik 
@nixCraft
Its the first thing you should check before starting your program logic.
Its the first thing you should check before starting your program logic.
Freevolt@nixCraft It's like a halting problem reborn.
Den of Earthint32 is_computer_on ()
{
return 1;
}
Alex Celeste, Princess Consort of Burnout
IAG
Dziadek@nixCraft You can’t get more Schrödinger than that.
mjdxp@nixCraft use this instead of "true" for better code obfuscation
The Penguin of Evil@nixCraft Absolute pig of a function to implement on a virtual machine that can be migrated
Electron Dance
_"DEVICE NUMBER GRATER" ???
Locksmith@nixCraft
I ran this function here. It returned a number that seemed a memory address. I checked the address and there was a string there: "I am."
What does this mean? What does this mean???
L@nixCraft function Is_Computer_On return Boolean;
Weekend EditorIt's a perfectly decent function... just a *partial* function, i.e., not defined on all its inputs.
Perfectly decent thing to be.
mirabilos@nixCraft int32 vorallendingen… 🤦
dr. fennec 
@nixCraft was the image description made by OCR? the function name reads "18_computer_on" instead of "is_computer_on"
vimprovedIf the computer isn't on, the value returned by this function is undefined.
goddamnit undefined behavior has gone too far
Western Infidels@nixCraft It's not much use without the companion functions
well_turn_it_on_then() and
sheesh_why_do_I_have_to_think_of_everything_myself_around_here()
arceuthobium@WesternInfidels @nixCraft it definitely needs an is_computer_plugged_in() extension
Robert Kist 🇦🇹🇸🇬@nixCraft Schrödinger's computer: it might be on, it might be off, you'll never know until you call this function
Paul Oldham 🏴 💛 🇺🇦@nixCraft I'm reminded of the vital opcodes for power saving in CPUs
TPF turn processor off
TPO turn processor on
TPF turn processor off
TPO turn processor on
Hugo 雨果
@whynothugo @nixCraft I hate it when the software updates with a new random number
Kaley@nixCraft sounds like a recipe for a secure memory leak issue to me 😛
David Chisnall (*Now with 50% more sarcasm!*)@nixCraft This is from the BeOS manual. As I recall, there is also an is_computer_on_fire() function, though I believe it always returned false in shipping versions.
EDIT: I forgot how silly the second one is. It's defined to return the temperature if the computer is on fire and some other value if not.
mORA@nixCraft I hope there will be a native version for 64 bit architectures anytime soon.
masukomi@nixCraft a close runner-up for "perfect function" from BeOS.
It’d be better if it returned a boolean.
blausand 🐟@nixCraft
bool is_computer();
// returns true if executed on a computer
// never returns when not executed on a computer
PS.: <pre> tag when, Mastodon?
Todd Thomas
Parsingphase
Brian Swetland
majick@nixCraft
The good old "lp0 on fire" error dating back to ancient times of yore is still a thing. And yes, it can still be thrown when the 8255 kicks an INTR-A.
It's in lp_check_status(), which is very much in the hot code path for local printing.
thorsummoner@nixCraft what's perfect about this!? An off computer can clearly read a 1 in some cases?!?!/s
Wilfried Klaebe@nixCraft Is there a nodejs module with this?
🇺🇸 🇺🇦 🇮🇱 🐧 🥦
René Vincent Jansen@nixCraft bios function was better: this was defined to return 0 if there was no power; you could prove this with a logic probe
ShutterBugged@nixCraft not TOCTOU safe 😂
GrendelI'm not sure a function is sufficient, this requires at least a library, if not a bloated trendy framework.
-rb@nixCraft uhhh, undefined means it could return 1, so you can’t even guarantee that a return value of 1 means that the computer is on.
Software is hard.
Kelvin n0mql EN35ld
haggai_e@nixCraft
😂
I guess it could be useful for intermittent computing (e.g., https://cmuabstract.github.io/intermittence_tutorial/)
😂
I guess it could be useful for intermittent computing (e.g., https://cmuabstract.github.io/intermittence_tutorial/)
AlisonW ♿🏳️🌈♾️@nixCraft
I suppose it could be a valid test for a remote target.
I suppose it could be a valid test for a remote target.