BYTEORDER(9)

okay bestie, welcome to the BYTEORDER(9) page from the Kernel Developer's Manual — this is where all the byte order operations live, and they are so ready to help. ✨

🌸 NAME 🌸

this page is the home of the whole byte-order squad: bswap16, bswap32, bswap64, be16toh, be32toh, be64toh, htobe16, htobe32, htobe64, htole16, htole32, htole64, le16toh, le32toh, le64toh, be16enc, be16dec, be32enc, be32dec, be64enc, be64dec, le16enc, le16dec, le32enc, le32dec, le64enc, le64dec — byte order operations. periodt. 💅

✨ SYNOPSIS ✨

#include <sys/endian.h>

uint16_t
bswap16(uint16_t int16);

uint32_t
bswap32(uint32_t int32);

uint64_t
bswap64(uint64_t int64);

uint16_t
be16toh(uint16_t big16);

uint32_t
be32toh(uint32_t big32);

uint64_t
be64toh(uint64_t big64);

uint16_t
htobe16(uint16_t host16);

uint32_t
htobe32(uint32_t host32);

uint64_t
htobe64(uint64_t host64);

uint16_t
htole16(uint16_t host16);

uint32_t
htole32(uint32_t host32);

uint64_t
htole64(uint64_t host64);

uint16_t
le16toh(uint16_t little16);

uint32_t
le32toh(uint32_t little32);

uint64_t
le64toh(uint64_t little64);

uint16_t
be16dec(const void *);

uint32_t
be32dec(const void *);

uint64_t
be64dec(const void *);

uint16_t
le16dec(const void *);

uint32_t
le32dec(const void *);

uint64_t
le64dec(const void *);

void
be16enc(void *, uint16_t);

void
be32enc(void *, uint32_t);

void
be64enc(void *, uint64_t);

void
le16enc(void *, uint16_t);

void
le32enc(void *, uint32_t);

void
le64enc(void *, uint64_t);

💖 DESCRIPTION 💖

okay so real talk, these functions are all about moving integers between byte orders, and each little group has its own job. no cap:

• bswap16(), bswap32(), bswap64() — these return a byte order swapped integer. On big endian systems, the number is converted to little endian byte order. On little endian systems, the number is converted to big endian byte order. literally the flip squad. 🔄
• be16toh(), be32toh(), be64toh() — these return a big endian byte ordered integer converted to the system's native byte order. The return value will be the same as the argument on big endian systems. 💖
• le16toh(), le32toh(), le64toh() — these return a little endian byte ordered integer converted to the system's native byte order. The return value will be the same as the argument on little endian systems. 🦋
• htobe16(), htobe32(), htobe64() — these return an integer in the system's native byte order converted to big endian byte order. The return value will be the same as the argument on big endian systems. ✨
• htole16(), htole32(), htole64() — these return an integer in the system's native byte order converted to little endian byte order. The return value will be the same as the argument on little endian systems. 🌸
• be16enc(), be16dec(), be32enc(), be32dec(), be64enc(), be64dec(), le16enc(), le16dec(), le32enc(), le32dec(), le64enc(), le64dec() — these encode and decode integers to/from byte strings on any alignment in big/little endian format. iconic behavior, honestly. 👑

👀 SEE ALSO 👀

you already know the vibe, but the official SEE ALSO bestie is byteorder(3). 🫶

🕰️ HISTORY 🕰️

• The hto*() and *toh() functions first appeared in FreeBSD 5.0, and were originally developed by the NetBSD project. 💜
• The encode/decode functions first appeared in FreeBSD 5.1. ⭐

mwah 💋 — this page comes from Debian, dated April 29, 2002, and its manual-page tag is BYTEORDER(9). love that for us. 🎀