1、struct in_addr
struct in_addr就是32位IP地址。
struct in_addr {
union {
struct { u_char s_b1,s_b2,s_b3,s_b4; } S_un_b;
struct { u_short s_w1,s_w2; } S_un_w;
u_long S_addr;
} S_un;
#define s_addr S_un.S_addr
};
2、sockaddr_in
struct sockaddr_in {
short int sin_family;
unsigned short int sin_port;
struct in_addr sin_addr;
unsigned char sin_zero[8];
};
sockaddr_in 结构体里面包含结构体in_addr,这是他们的关系
inet_addr()是将一个点分制的IP地址(如192.168.0.1)转换为上述结构中需要的32位IP地址(0xC0A80001)
一般用法
struct sockaddr_in sockaddr;
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(MYPORT);
sockaddr.sin_addr.s_addr = inet_addr("192.168.0.1");
