TIOCSTI(2const)

✨ TIOCSTI ✨

okay so bestie, welcome to the TIOCSTI page 💖 it lives in the 2const section of the manual (that's the const-y corner of section 2, iykyk), and it's literally all about faking input. yes fr fr, you can just. shove a byte into a terminal's input queue like you're typing it yourself. main character energy 🎀

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📚 LIBRARY

Standard C library (libc, -lc) 🫶

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🌸 SYNOPSIS

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

int ioctl(int fd, TIOCSTI, const char *argp);

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💅 DESCRIPTION

So what it does: insert the given byte in the input queue. that's it, that's the whole vibe. one byte, straight into the queue, like it came from the keyboard itself 😭

⚠️ okay but heads up, because since Linux 6.2 this operation may require the CAP_SYS_ADMIN capability — and that only kicks in if the dev.tty.legacy_tiocsti sysctl variable is set to false. so if it's giving permission-denied, that's why bestie 🙈

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🫶 RETURN VALUE

• On success, 0 is returned ✨
• On error, -1 is returned, and errno is set to indicate the error 💀

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🔥 ERRORS

• EPERM — Insufficient permission. that's the one, that's the whole list, no cap 👑

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👀 SEE ALSO

• ioctl(2)
• ioctl_tty(2)

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💜 and that's the page!! this one came from Linux man-pages 6.20, dated 2026-02-08 — so if you're reading it later, don't come for me, come for the man-pages maintainers 🧚 slay, bye bestie! 🌈⭐