vt_do_diacrit(9)

💅 vt_do_diacrit(9) — the Kernel API Manual moment

okay so bestie, welcome to vt_do_diacrit(9), a genuine little kernel-API-manual icon ✨ stick around, this one's short but it matters.

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✨ SYNOPSIS ✨

int vt_do_diacrit (unsigned int cmd , void __user *udp , int perm );

like, that's the whole vibe. three args, one int coming back at you 🫶

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🎀 ARGUMENTS 🎀

• cmd — the ioctl request, iykyk. this is the "what do you actually want" of it all.
• udp — pointer to user data for the ioctl. userland hands you the goods through here 💌
• perm — the permissions check, already computed by the caller. not your problem, they did the homework 🌸

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🦋 DESCRIPTION 🦋

So here's the tea: this function updates the diacritical tables, and it does it atomically and safely. No half-updated table era, no cursed in-between state, we simply don't do that here 💅

And because keypresses can literally arrive at any moment (rude, but okay), it locks the tables against simultaneous keypresses. that's the whole point, that's the slay. your diacritics stay consistent even when the keyboard is being a main character 🔥

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👑 SEE ALSO 👑

Kernel file ./drivers/tty/vt/keyboard.c — go read it, it's giving lore 📖

and the whole friend group:

• vt_get_leds(9)
• vt_set_led_state(9)
• vt_kbd_con_start(9)
• vt_kbd_con_stop(9)
• vt_do_kdskbmode(9)
• vt_do_kdskbmeta(9)
• vt_do_kdgkbmeta(9)
• vt_reset_unicode(9)
• vt_get_shift_state(9)
• vt_reset_keyboard(9)
• vt_get_kbd_mode_bit(9)
• vt_set_kbd_mode_bit(9)
• vt_clr_kbd_mode_bit(9)

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mwah 💋 that's the page. this one lives in ./drivers/tty/vt and it's stamped October 2026, so jot that down — fr fr, see you in the next one, bestie 🎀✨