如何在基于Debian的系统上以编程方式获取IP地址？

#include<stdio.h>
#include <stdlib.h>
#include<string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <ifaddrs.h>
#include <net/if.h>

int main() {
    struct ifaddrs *ifaddr, *ifa;
    int family, s;
    char host[NI_MAXHOST];

    if (getifaddrs(&ifaddr) == -1) {
        perror("getifaddrs");
        exit(EXIT_FAILURE);
    }

    for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
        if (ifa->ifa_addr == NULL)
            continue;

        family = ifa->ifa_addr->sa_family;

        if (family == AF_INET) {
            s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in),
                    host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
            if (s != 0) {
                printf("getnameinfo() failed: %s\n", gai_strerror(s));
                continue;
            }

            printf("Interface: %s\tIPv4 address: %s\n", ifa->ifa_name, host);
        } else if (family == AF_INET6) {
            s = getnameinfo(ifa->ifa_addr, sizeof(struct sockaddr_in6),
                    host, NI_MAXHOST, NULL, 0, NI_NUMERICHOST);
            if (s != 0) {
                printf("getnameinfo() failed: %s\n", gai_strerror(s));
                continue;
            }

            printf("Interface: %s\tIPv6 address: %s\n", ifa->ifa_name, host);
        }
    }

    freeifaddrs(ifaddr);
    return 0;
}

import socket
import fcntl
import struct

def get_ip_address(ifname):
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    info = fcntl.ioctl(s.fileno(), 0x8915, struct.pack('256s', ifname[:15].encode('utf-8')))
    return socket.inet_ntoa(info[20:24])

print(get_ip_address('eth0'))