kdb_position_cursor(9)

💅 kdb_position_cursor(9) — like, the Kernel API Manual page you actually wanna read 🎀

okay so bestie, this is kdb_position_cursor from the kdb_position_cursor(9) section of the Kernel API Manual, and it's genuinely such a little icon. let's get into it 💖

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✨ NAME ✨

kdb_position_cursor — places the cursor in the correct horizontal position 🫶 (yes that's it, that's the whole job, and she does it flawlessly)

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🌸 SYNOPSIS 🌸

void kdb_position_cursor (char *prompt , char *buffer , char *cp );

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🦋 ARGUMENTS 🦋

• prompt — a Nil-terminated string holding the prompt string 💅 like, the whole prompt, nil-terminated, that's the vibe
• buffer — a Nil-terminated string with the entire command line in it. the whole thing. iconic.
• cp — the cursor position: a pointer to the character in buffer where the cursor should be positioned 👑

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💜 DESCRIPTION 💜

so the way this works is: the cursor gets positioned by sending a carriage-return, and then printing the content of the line until we reach the correct cursor position. that's the whole move. CR, then print, then boom — cursor's where it needs to be. slay ✨

but there's some additional fine detail here, and ngl it's giving "the devs thought about this very hard":

Firstly — even though kdb_printf will correctly format zero-width fields, we want the second call to kdb_printf to be conditional. that keeps things a little cleaner when LOGGING=1. lowkey a whole vibe check on the logging situation 🩷

Secondly — we can't combine everything into one call to kdb_printf, because that renders into a fixed length buffer and the combined print could result in unwanted truncation. 😭 so yeah, two calls. not optional. the truncation would simply be too tragic.

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🌈 SEE ALSO 🌈

• Kernel file ./kernel/debug/kdb/kdb_io.c — go read her, iykyk
• kdb_handle_escape(9)
• kdb_getchar(9)

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fr fr, if you're poking around in kdb cursor math, you already know what time it is 💀 no cap.

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and that's the page bestie 🎀 one last thing — this beauty lives under ./kernel/debug/kdb, dated October 2026, and it's giving main character energy from the very last line. mwah 💋🌸