c常用头文件——netinet/in.h

#include <netinet/in.h>

1、socketaddr_in 结构体

struct sockaddr_in

eg:

#define SERV_PORT 6666

struct sockaddr_in serveraddr;

serveraddr.sin_family=AF_INET;

serveraddr.sin_port=htons(SERV_PORT);

2、htons系统调用

extern uint16_t htons (uint16_t __hostshort) 

     __THROW __attribute__ ((__const__));

eg:

#define SERV_PORT 6666

serveraddr.sin_port=htons(SERV_PORT);