wdt_write(9)

📦 version 7.3.1, in nixpkgs unstable

💅 wdt_write(9) — from the Kernel API Manual, bestie 🐶

okay so this is a page straight out of the Kernel API Manual, and it's about the function wdt_write — one of the watchdog crew. yes, literally a function whose whole personality is "i'm alive, i'm alive, i'm alive." let's get into it 🫶

✨ NAME ✨

wdt_write —

and that's it. that's the whole NAME section. no description, no little tagline, nothing. it's giving minimalism, it's giving "i said what i said." the manpage authors left this one blank, so we're not gonna invent lore that isn't there. respect the silence 💀

🦋 SYNOPSIS 🦋

ssize_t wdt_write (struct file *file , const char __user *buf , size_t
count , loff_t *ppos );

periodt. that's the signature, copied exactly, spaces and all — don't come for me about the spacing, that's how the original rolls 😌

🎀 ARGUMENTS 🎀

so every one of these matters, iykyk:

  • file — the file handle to the watchdog. that's your little entry pass into watchdog land 👑
  • buf — the buffer to write. and here's the iconic part: it's unused, because the data does not matter here. literally write whatever, the watchdog does not care, it has no opinions about your content 🫶 (original says: buffer to write (unused as data does not matter here — and no, that unclosed paren is not my typo, it's canon 🙈)
  • count — count of bytes. yes. how many bytes you're throwing at it. even though the bytes are meaningless, the count is a real parameter, so it's here 💅
  • ppos — pointer to the position to write. and hard rule: no seeks allowed. none. zero. don't even think about it 🚫

🌸 DESCRIPTION 🌸

kay so here's the vibe check: a write to a watchdog device is defined as a keepalive signal. that's the whole thing. that's the assignment 🐕✨

any write of data will do — literally any of it — because we don't define content meaning. the bytes are just a little "hey bestie, still here, still kicking" note. it's not about what you write, it's about the fact that you wrote something. main character energy of the highest order 👑

🦋 SEE ALSO 🦋

the kernel file lives at ./drivers/watchdog/wdt.c, and here's the whole squad, all of them, no one left behind 💜:

like, the entire friend group 💖

little reminder bestie: buf's data genuinely does not matter, and ppos genuinely does not allow seeks. those are the two facts to hold in your heart 🫶

and that's the page!! coming to you from the source path ./drivers/watchdog, dated October 2026 — mwah, mwah, go ping your watchdogs, ily, bye 🎀✨💜

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