HTOBE64(3) | Library Functions Manual | HTOBE64(3) |

`htobe64`

, `htobe32`

,
`htobe16`

, `be64toh`

,
`be32toh`

, `be16toh`

,
`betoh64`

, `betoh32`

,
`betoh16`

, `htole64`

,
`htole32`

, `htole16`

,
`le64toh`

, `le32toh`

,
`le16toh`

, `letoh64`

,
`letoh32`

, `letoh16`

,
`swap64`

, `swap32`

,
`swap16`

—
convert values between different byte orderings

`#include <endian.h>`

`uint64_t`

`htobe64`

(`uint64_t
host64`);

`uint32_t`

`htobe32`

(`uint32_t
host32`);

`uint16_t`

`htobe16`

(`uint16_t
host16`);

`uint64_t`

`be64toh`

(`uint64_t
big64`);

`uint32_t`

`be32toh`

(`uint32_t
big32`);

`uint16_t`

`be16toh`

(`uint16_t
big16`);

`uint64_t`

`betoh64`

(`uint64_t
big64`);

`uint32_t`

`betoh32`

(`uint32_t
big32`);

`uint16_t`

`betoh16`

(`uint16_t
big16`);

`uint64_t`

`htole64`

(`uint64_t
host64`);

`uint32_t`

`htole32`

(`uint32_t
host32`);

`uint16_t`

`htole16`

(`uint16_t
host16`);

`uint64_t`

`letoh64`

(`uint64_t
little64`);

`uint64_t`

`le64toh`

(`uint64_t
little64`);

`uint32_t`

`le32toh`

(`uint32_t
little32`);

`uint16_t`

`le16toh`

(`uint16_t
little16`);

`uint32_t`

`letoh32`

(`uint32_t
little32`);

`uint16_t`

`letoh16`

(`uint16_t
little16`);

`uint64_t`

`swap64`

(`uint64_t
val64`);

`uint32_t`

`swap32`

(`uint32_t
val32`);

`uint16_t`

`swap16`

(`uint16_t
val16`);

Apart from the swap functions, the names containing “be” convert between host and big-endian (most significant byte first) order of the given quantity, while the names containing “le” convert between host and little-endian (least significant byte first) order of the given quantity.

All these functions use the numbers 16, 32, or 64 for specifying the bitwidth of the quantities they operate on. Currently all supported architectures are either big- or little-endian so either the “be” or “le” variants are implemented as null macros.

`htobe64`

(), `htobe32`

(),
`htobe16`

(), `be64toh`

(),
`be32toh`

(), `be16toh`

(),
`htole64`

(), `htole32`

(),
`htole16`

(), `le64toh`

(),
`le32toh`

(), and `le16toh`

()
functions are expected to conform to a future version of IEEE
Std 1003.1 (“POSIX.1”). The other functions are
extensions that should not be used when portability is required.
`swap{size}`

and
`{src-order}to{dst-order}{size}`

functions appeared in
4.2BSD. The
`{src-order}{size}to{dst-order}`

functions appeared in
OpenBSD 5.6. A subset of them was submitted for
standardization after IEEE Std 1003.1-2008
(“POSIX.1”).
November 10, 2015 | OpenBSD-current |