ctrlchar_handle(9)

💅 ctrlchar_handle(9) — a Kernel API Manual moment

okay so this is a page from the Kernel API Manual (yes, the whole manual, we're fancy) and today's main character is ctrlchar_handle — the function that literally just peeks at the beginning of your input and goes "hmm, is there a special char in here bestie?" 🕵️‍♀️✨

---

🌸 NAME 🌸

ctrlchar_handle — check for special chars at start of input 👀

---

🎀 SYNOPSIS 🎀

unsigned int ctrlchar_handle (const unsigned char *buf , int len ,
       struct tty_struct *tty );

like, that's the whole signature, no notes 💅

---

💖 ARGUMENTS 💖

• buf — console input buffer. this is the vibe check zone, the place where the good stuff lives 🫶
• len — length of valid data in buffer. i.e. how much of buf is actually real and not just leftover sadness 💀
• tty — the tty struct for this console. your console's whole personality, basically 👑

---

✨ RETURN ✨

here's the tea, it returns one of these bad boys ☕:

• CTRLCHAR_NONE — if nothing matched. no special char, no drama, we move on 🙈
• CTRLCHAR_SYSRQ — if sysrq was encountered. iconic, honestly 🔥
• otherwise, the char to be inserted logically or'ed with CTRLCHAR_CTRL — like the char got its little CTRLCHAR_CTRL accessory on 🎀

---

🦋 SEE ALSO 🦋

Kernel file ./drivers/s390/char/ctrlchar.c — go read it, it's giving source code realness 📖💜

---

and that's the whole page, bestie!! this slay of a manpage came from ./drivers/s390/char and is dated October 2026 — no cap, screenshot it for the group chat 📸✨💅