Host和网路字节序的转换

        有4个函数用于字节序的转换。分别针对2字节和4字节。单个字节自然没有字节序的问题。

htonl(3) - Linux man page

Name

htonl, htons, ntohl, ntohs - convert values between host and network byte order

Synopsis

#include <arpa/inet.h>
uint32_t htonl(uint32_t hostlong);
uint16_t htons(uint16_t hostshort);
uint32_t ntohl(uint32_t netlong);
uint16_t ntohs(uint16_t netshort);

Description

The  htonl() function converts the unsigned integer  hostlong from host byte order to network byte order.

The htons() function converts the unsigned short integer hostshort from host byte order to network byte order.

The ntohl() function converts the unsigned integer netlong from network byte order to host byte order.

The ntohs() function converts the unsigned short integer netshort from network byte order to host byte order.

On the i80x86 the host byte order is Least Significant Byte first, whereas the network byte order, as used on the Internet, is Most Significant Byte first.

Conforming to

POSIX.1-2001.

Some systems require the inclusion of <netinet/in.h> instead of <arpa/inet.h>.

See Also

gethostbyname(3),  getservent(3)