注：头文件请自己查询

windows平台

#pragma comment(lib,"ws2_32.lib")   //for gethostname
#define BUF_LEN 1024

void getHostnameAndip() {
    int iRet = 0;
    WSADATA wsaData;

    if (iRet = (WSAStartup(MAKEWORD(2, 2), &wsaData)) != 0) {
        printf("WSAStartup  Failed!\n");
        return;
    }

    char cHostName[BUF_LEN] = { 0 };
    if ((iRet = gethostname(cHostName, BUF_LEN)) != 0) {
        printf("gethostname()  Failed!\n");
        return;
    }

    HOSTENT *host = gethostbyname(cHostName);
    if (NULL == host) {
        printf("gethostbyname failed!\n");
        return;
    }

    printf("cHostName  %s\n", cHostName);
    for (int i = 0;; ++i) {
        char *pIpaddr = host->h_addr_list[i];
        if (NULL == pIpaddr)    return;

        in_addr addr;
        memcpy(&addr, pIpaddr, host->h_length); 

        printf("cHost ip  %d.%d.%d.%d\n", addr.S_un.S_un_b.s_b1, addr.S_un.S_un_b.s_b2, addr.S_un.S_un_b.s_b3, addr.S_un.S_un_b.s_b4);
    }
}

linux平台

#define BUF_LEN 1024
void getIP(){
        char    hostname[BUF_LEN];
        struct  hostent *host;  
        int     i = 0;

        memset(hostname, 0, BUF_LEN);
        gethostname(hostname, sizeof(hostname));

        host = gethostbyname(hostname);

        printf("\nhostname: %s\n", hostname);
//      printf("hostname: %s\n", host->h_name);
        for (; host->h_addr_list[i]; ++i){
                printf("ip : %s\n", inet_ntoa(*(struct in_addr*)(host->h_addr_list[i])));
        }
}

python

import socket

def showHostIP():
        sk = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        hostname = socket.gethostname()
        print("hostname = %s" % hostname)
        ip = socket.gethostbyname(hostname)
        iplist = socket.gethostbyname_ex(hostname)
        print(ip)
        print(iplist)

shell

function showHost(){
        uname -n
        ifconfig | grep "inet addr" | while read ipaddr;    do
           ipaddr=${ipaddr#*:} && ipaddr=${ipaddr%% *}
        done
}