ioctl_tty(2)

📦
version 6.20 · 13 versions
, in arch rolling, nixpkgs unstable

✨ ioctl_tty ✨

okay bestie so this is ioctl_tty(2) — the manual page for all the ioctls your terminal and your serial lines use 💖 it's a system call page, and yeah it's a lot, but we're gonna get through it together.

🎀 NAME 🎀

ioctl_tty — the ioctls for terminals and serial lines. that's it, that's the whole vibe 🦋

📚 LIBRARY 📚

Standard C library (libc, -lc) — your usual ride-or-die. 💅

🌸 SYNOPSIS 🌸

#include <asm/termbits.h>  /* Definition of constants */
#include <sys/ioctl.h>

int ioctl(int fd, int op, ...);

no cap, those two headers are the whole entrance fee. asm/termbits.h is where the constants live, and sys/ioctl.h is where the actual ioctl() lives. 🫶

💜 DESCRIPTION 💜

so ioctl(2) — when you point it at a terminal or a serial port — accepts a whole menu of possible operation arguments. not a small menu. a big one. like a Cheesecake Factory menu. 😭

Most of them want a third argument, and the type varies, so this page calls it argp or arg. don't ask why there's two names, it's giving legacy, we love her anyway. 🎀

⚠️ real talk though: using ioctl() means your program is nonportable. fr fr. the POSIX interface described in termios(7) is the move whenever you can possibly swing it. ioctl() is the "I know what I'm doing and I accept the consequences" route. 💀

👑 Get and set terminal attributes 👑

the big ones. the main characters. 🌟

three little families, all doing the get-and-set terminal attributes thing. the 2 girlies are their own cluster, the A girlies are their own cluster, and the originals are just out here being iconic. 🦋

🔒 Locking the termios structure 🔒

keeping that termios struct from being messed with behind your back. so protective, we stan. 💖

🪟 Get and set window size 🪟

window size!! the thing every TUI is secretly screaming about. 🌈

💥 Sending a break 💥

break time. literally. sending a break. ✨ (not a snack break, sadly. 🍓)

🌊 Software flow control 🌊

just the one. she's solo and she's fine with it. 💅

📦 Buffer count and flushing 📦

how much is sitting in there, and how to yeet it out. 🔥

🙈 Faking input 🙈

it's giving "pretend the user typed this." dramatic. iconic. chaotic. 🎀

🖥️ Redirecting console output 🖥️

🧚 Controlling terminal 🧚

grabbing the controlling tty, and then letting it go like a situationship. 😭

👯 Process group and session ID 👯

🚫 Exclusive mode 🚫

get, set, unset. the full trio, no notes. 💜

🛤️ Line discipline 🛤️

🐚 Pseudoterminal ioctls 🐚

the pty girlies!! lowkey the most fun group here. 🫶

📞 Modem control 📞

yes we still do modems. heritage. history. respect. 👑

🏠 Marking a line as local 🏠

🐧 Linux-specific 🐧

for the TIOCLINUX(2const) ioctl, go look at ioctl_console(2) instead — it lives over there, this page is not her home. 🏡

🐛 Kernel debugging 🐛

💫 RETURN VALUE 💫

  • on success? 0 is returned. slay. ✨
  • on error? -1 is returned, and errno gets set to indicate the error. so always check that errno, bestie, it's telling you the tea. 😭

🔗 SEE ALSO 🔗

that's the whole page 💖 you made it to the end, I'm so proud of you, actual main character energy.

this came from Linux man-pages 6.20, dated 2026-07-02 — yeah she's from the future, we don't ask questions. 🦋✨💅

📦 where this page comes from
  • arch rolling: man-pages 6.20-1 · BSD-2-Clause AND BSD-3-Clause AND BSD-4.3TAHOE AND BSD-4-Clause-UC AND GPL-1.0-or-later AND GPL-2.0-only AND GPL-2.0-or-later AND GPL-3.0-or-later AND LGPL-3.0-linking-exception AND LGPL-3.0-or-later AND LicenseRef-Public-Domain AND LicenseRef-UltraPermissive AND Linux-man-pages-1-para AND Linux-man-pages-copyleft AND Linux-man-pages-copyleft-2-para AND Linux-man-pages-copyleft-var AND MIT AND Spencer-94
  • nixpkgs unstable: man-pages 6.20
  • 📜 the page's license: GPL-1.0-or-later
  • Copyright 2002, Walter Harms <walter.harms@informatik.uni-oldenburg.de>
  • Copyright 2002, Andries Brouwer <aeb@cwi.nl>
  • 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms