PR_SET_ENDIAN(2const)

🎀 PR_SET_ENDIAN — the endianness glow-up 💅

okay so this is from the PR_SET_ENDIAN(2const) manual page, and bestie, it's a whole little vibe. It lives in the Standard C library (libc, -lc) — yes, the standard girly. 🌸

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✨ NAME ✨

PR_SET_ENDIAN — set endianness of the calling process 🦋

Lowkey the whole personality of this call: it flips your process's byte-order aesthetic. Big or little? That's the question. 👑

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✨ LIBRARY ✨

Standard C library (libc, -lc) 💖

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✨ SYNOPSIS ✨

#include <linux/prctl.h>  /* Definition of PR_* constants */
#include <sys/prctl.h>

int prctl(PR_SET_ENDIAN, long endianness);

Not me making you include two headers 🙈 but yes, both. linux/prctl.h is where the PR_* constants live, and sys/prctl.h is the actual prctl() doorway. You need them both, fr fr.

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✨ DESCRIPTION ✨

So basically you're setting the endianness of the calling process to whatever value you pass in endianness. 🎀

That endianness argument should be one of these three icons:

• PR_ENDIAN_BIG — big endian energy 🔥
• PR_ENDIAN_LITTLE — little endian energy 🍓
• PR_ENDIAN_PPC_LITTLE — the PowerPC pseudo little endian one (iykyk, it's a whole special PowerPC situation) 💜

no cap, it needs to be one of those three — anything else and it's not going to go the way you want it to. See ERRORS below, bestie. 😭

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✨ RETURN VALUE ✨

• On success → 0 is returned. slay. ✨
• On error → -1 is returned, and errno gets set to tell you what went wrong. 💀

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✨ ERRORS ✨

• EINVAL — endianness is not a valid value. literally the only way this throws hands. 🫶

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✨ STANDARDS ✨

Linux. And PowerPC only — this is not a general population call, it's giving exclusive invite. 👑

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✨ HISTORY ✨

Linux 2.6.18 (PowerPC). vintage. iconic. a classic. 🌈

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✨ SEE ALSO ✨

• prctl(2)
• PR_GET_ENDIAN(2const)

(yes bestie, there's a getter — go read it, the pair is adorable 🥰)

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mwah 💋 this page is from Linux man-pages 6.20, dated 2026-02-08 — so you know it's fresh, it's current, and it's serving exactly what the kernel ordered. 💖✨🎀