获取本机IP地址和主机名

#include <stdio.h>
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib")

int main(int argc, char **argv)
{
    WSADATA wsaData;
    WORD    wVersion = MAKEWORD(2, 2);
    if(::WSAStartup(wVersion, &wsaData) != 0)       //初始化套接字库
    {
        printf("Initialize the socket failed\n");
        return 0;
    }

    char szHostName[256];
    ::gethostname(szHostName, sizeof(szHostName)); //获取主机名
    printf("主机名：%s\n", szHostName);

    hostent *pHost = ::gethostbyname(szHostName);  //通过主机名获取IP

    //打印出所有的IP地址
    in_addr addr;
    for(int i = 0; ; i++)
    {
        char *p = pHost->h_addr_list[i];
        if(p == NULL)
            break;

        memcpy(&addr.S_un.S_addr, p, pHost->h_length);
        char *szIp = ::inet_ntoa(addr);

        printf("本机IP地址：%s\n", szIp);
    }

    return 0;
}