Network Endianness

When handling binary data transmitted or shared across platforms, you need be concerned with how each platform stores numerical values. A platform stores values either in big-endian or little-endian format. On big-endian machines, such as PowerPC machines, values are stored with the most-significant bytes first in memory; on little-endian machines, such as Pentium machines, values are stored with the least-significant bytes first. A multibyte value transmitted to a platform with a different format will be misinterpreted if it is not converted properly by one of the computers.

#include <sys/_endian.h>

#define ntohs(x)    __DARWIN_OSSwapInt16(x)
#define htons(x)    __DARWIN_OSSwapInt16(x)

#define ntohl(x)    __DARWIN_OSSwapInt32(x)
#define htonl(x)    __DARWIN_OSSwapInt32(x)

In Swift

CFSwapInt32()

instead of

ntonl() and ntohl()

and

CFSwapInt16()

instead of

ntons() and ntohs()

Reference:How do I set integer endianness using htonl in Swift?