SWAB(3P)

📦 version 2017a, in alpine 3.22, alpine 3.23, alpine 3.24, arch rolling, nixpkgs unstable, opensuse-leap 16.0

💖 PROLOG 💖

Okay bestie, so before we even get into it — this manual page is part of the POSIX Programmer's Manual. Important tea: the Linux implementation of this interface may differ, so if you're on Linux you gotta go consult the corresponding Linux manual page for the deets on Linux behavior. Or, plot twist, the interface might not even be implemented on Linux at all. 🙈 Just so you know going in.

✨ NAME ✨

swab — swap bytes 🦋

🌸 SYNOPSIS 🌸

#include <unistd.h>

void swab(const void *restrict src, void *restrict dest,
    ssize_t nbytes);

💅 DESCRIPTION 💅

So swab() shall copy nbytes bytes — the ones pointed to by src — over to the object pointed to by dest, exchanging adjacent bytes as it goes. Like it's literally swapping every neighboring pair, no cap.

The nbytes argument should be even. If nbytes is odd, swab() copies and exchanges nbytes-1 bytes, and the disposition of that last byte is unspecified — so don't come crying to me about that one byte, it's giving mystery. 🔥

If copying takes place between objects that overlap, the behavior is undefined. Bestie. Do not. 🚫

And if nbytes is negative, swab() does nothing. Just sits there. Main character energy of doing absolutely nothing. 💀

🎀 RETURN VALUE 🎀

None. That's it, that's the whole section. It returns nothing, periodt.

🌈 ERRORS 🌈

No errors are defined. Iconic behavior honestly — nothing to report, no drama.

The following sections are informative.

🍓 EXAMPLES 🍓

None.

🧚 APPLICATION USAGE 🧚

None.

⭐ RATIONALE ⭐

None.

🦋 FUTURE DIRECTIONS 🦋

None.

👑 SEE ALSO 👑

The Base Definitions volume of POSIX.1‐2017, <unistd.h>

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

And that's the whole thing, bestie — courtesy of IEEE/The Open Group, 2017. Go forth and swap those bytes responsibly. 💖✨

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