n_hdlc_tty_read(9)

📦 version 7.3.1, in nixpkgs unstable

💖 n_hdlc_tty_read(9) 💖

okay so this is a page straight out of the Kernel API Manual, bestie — it's called n_hdlc_tty_read, and it's literally the function that gets called to retrieve one frame of data (if available). yes, "if available" is doing a lot of work in that sentence, we love a conditional 💅

✨ SYNOPSIS ✨

ssize_t n_hdlc_tty_read (struct tty_struct *tty , struct file *file , u8
*kbuf , size_t nr , void **cookie , unsigned long offset );

that's it, that's the whole vibe. ssize_t return, six arguments, no notes 🎀

🦋 ARGUMENTS 🦋

  • tty — pointer to tty instance data. it's giving "the actual device we're talking to" energy ✨
  • file — pointer to open file object. the file that's, y'know, open 👑
  • kbuf — pointer to returned data buffer. this is where the data goes to live 💖
  • nr — size of returned data buffer. how much room kbuf actually has, no cap 🌸
  • cookie — stored rbuf from previous run. yes it's literally called a cookie, and yes that's iconic 🍓
  • offset — offset into the data buffer. where in the buffer we're starting from 🧚

🔥 DESCRIPTION 🔥

Returns the number of bytes returned or error code. that's it. that's the whole description. short queen behavior, honestly 💀

like — read it, get a byte count, or get an error. no in-between, no extra lore, periodt ⭐

🌈 SEE ALSO 🌈

Kernel file ./drivers/tty/n_hdlc.c, plus the whole friend group 🫶:

lowkey a whole family reunion in that SEE ALSO list, and you're invited 💜

okay bye bestie, this page came from ./drivers/tty and it's dated October 2026 — go forth and read those frames, mwah 😭💅🦋

📦 where this page comes from