endian.h¶

Source code¶

// "License": Public Domain
// I, Mathias Panzenböck, place this file hereby into the public domain. Use it at your own risk for whatever you like.
// In case there are jurisdictions that don't support putting things in the public domain you can also consider it to
// be "dual licensed" under the BSD, MIT and Apache licenses, if you want to. This code is trivial anyway. Consider it
// an example on how to get the endian conversion functions on different platforms.

#ifndef PORTABLE_ENDIAN_H__
#define PORTABLE_ENDIAN_H__

#if (defined(_WIN16) || defined(_WIN32) || defined(_WIN64)) && !defined(__WINDOWS__)

#   define __WINDOWS__

#endif

#if defined(__linux__) || defined(__CYGWIN__)

#   include <endian.h>

#elif defined(__APPLE__)

#   include <libkern/OSByteOrder.h>

#   define htobe16(x) OSSwapHostToBigInt16(x)
#   define htole16(x) OSSwapHostToLittleInt16(x)
#   define be16toh(x) OSSwapBigToHostInt16(x)
#   define le16toh(x) OSSwapLittleToHostInt16(x)

#   define htobe32(x) OSSwapHostToBigInt32(x)
#   define htole32(x) OSSwapHostToLittleInt32(x)
#   define be32toh(x) OSSwapBigToHostInt32(x)
#   define le32toh(x) OSSwapLittleToHostInt32(x)

#   define htobe64(x) OSSwapHostToBigInt64(x)
#   define htole64(x) OSSwapHostToLittleInt64(x)
#   define be64toh(x) OSSwapBigToHostInt64(x)
#   define le64toh(x) OSSwapLittleToHostInt64(x)

#   define __BYTE_ORDER    BYTE_ORDER
#   define __BIG_ENDIAN    BIG_ENDIAN
#   define __LITTLE_ENDIAN LITTLE_ENDIAN
#   define __PDP_ENDIAN    PDP_ENDIAN

#elif defined(__OpenBSD__)

#   include <endian.h>

#   define __BYTE_ORDER    BYTE_ORDER
#   define __BIG_ENDIAN    BIG_ENDIAN
#   define __LITTLE_ENDIAN LITTLE_ENDIAN
#   define __PDP_ENDIAN    PDP_ENDIAN

#elif defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)

#   include <sys/endian.h>

#   define be16toh(x) betoh16(x)
#   define le16toh(x) letoh16(x)

#   define be32toh(x) betoh32(x)
#   define le32toh(x) letoh32(x)

#   define be64toh(x) betoh64(x)
#   define le64toh(x) letoh64(x)

#elif defined(__WINDOWS__)

#   include <winsock2.h>
#   ifdef __GNUC__
#       include <sys/param.h>
#   endif

#   if BYTE_ORDER == LITTLE_ENDIAN

#       define htobe16(x) htons(x)
#       define htole16(x) (x)
#       define be16toh(x) ntohs(x)
#       define le16toh(x) (x)

#       define htobe32(x) htonl(x)
#       define htole32(x) (x)
#       define be32toh(x) ntohl(x)
#       define le32toh(x) (x)

#       define htobe64(x) htonll(x)
#       define htole64(x) (x)
#       define be64toh(x) ntohll(x)
#       define le64toh(x) (x)

#   elif BYTE_ORDER == BIG_ENDIAN

        /* that would be xbox 360 */
#       define htobe16(x) (x)
#       define htole16(x) __builtin_bswap16(x)
#       define be16toh(x) (x)
#       define le16toh(x) __builtin_bswap16(x)

#       define htobe32(x) (x)
#       define htole32(x) __builtin_bswap32(x)
#       define be32toh(x) (x)
#       define le32toh(x) __builtin_bswap32(x)

#       define htobe64(x) (x)
#       define htole64(x) __builtin_bswap64(x)
#       define be64toh(x) (x)
#       define le64toh(x) __builtin_bswap64(x)

#   else

#       error byte order not supported

#   endif

#   define __BYTE_ORDER    BYTE_ORDER
#   define __BIG_ENDIAN    BIG_ENDIAN
#   define __LITTLE_ENDIAN LITTLE_ENDIAN
#   define __PDP_ENDIAN    PDP_ENDIAN

#elif defined(__QNXNTO__)

#   include <gulliver.h>

#   define __LITTLE_ENDIAN 1234
#   define __BIG_ENDIAN    4321
#   define __PDP_ENDIAN    3412

#   if defined(__BIGENDIAN__)

#       define __BYTE_ORDER __BIG_ENDIAN

#       define htobe16(x) (x)
#       define htobe32(x) (x)
#       define htobe64(x) (x)

#       define htole16(x) ENDIAN_SWAP16(x)
#       define htole32(x) ENDIAN_SWAP32(x)
#       define htole64(x) ENDIAN_SWAP64(x)

#   elif defined(__LITTLEENDIAN__)

#       define __BYTE_ORDER __LITTLE_ENDIAN

#       define htole16(x) (x)
#       define htole32(x) (x)
#       define htole64(x) (x)

#       define htobe16(x) ENDIAN_SWAP16(x)
#       define htobe32(x) ENDIAN_SWAP32(x)
#       define htobe64(x) ENDIAN_SWAP64(x)

#   else

#       error byte order not supported

#   endif

#   define be16toh(x) ENDIAN_BE16(x)
#   define be32toh(x) ENDIAN_BE32(x)
#   define be64toh(x) ENDIAN_BE64(x)
#   define le16toh(x) ENDIAN_LE16(x)
#   define le32toh(x) ENDIAN_LE32(x)
#   define le64toh(x) ENDIAN_LE64(x)

#else

#   error platform not supported

#endif

#endif
Updated on 2026-03-04 at 13:10:44 -0800