c 如何获取内网的ip地址

#include <stdio.h>
#include <winsock2.h>

#pragma comment(lib, "ws2_32.lib")

int main() {
    WSADATA wsaData;
    if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) {
        printf("WSAStartup failed.\n");
        return 1;
    }

    char hostname[256];
    if (gethostname(hostname, sizeof(hostname)) == SOCKET_ERROR) {
        printf("gethostname failed with error: %d\n", WSAGetLastError());
        WSACleanup();
        return 1;
    }

    struct addrinfo hints, *res, *ptr;
    ZeroMemory(&hints, sizeof(hints));
    hints.ai_family = AF_INET; // 使用IPv4
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;

    int status = getaddrinfo(hostname, NULL, &hints, &res);
    if (status != 0) {
        printf("getaddrinfo failed with error: %s\n", gai_strerror(status));
        WSACleanup();
        return 1;
    }

    for (ptr = res; ptr != NULL; ptr = ptr->ai_next) {
        struct sockaddr_in *ipv4 = (struct sockaddr_in *)ptr->ai_addr;
        char ipstr[INET_ADDRSTRLEN];
        inet_ntop(AF_INET, &(ipv4->sin_addr), ipstr, INET_ADDRSTRLEN);
        printf("Local IP address: %s\n", ipstr);
    }

    freeaddrinfo(res);
    WSACleanup();
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

int main() {
    char hostname[256];
    if (gethostname(hostname, sizeof(hostname)) != 0) {
        perror("gethostname");
        return 1;
    }

    struct addrinfo hints, *res, *ptr;
    memset(&hints, 0, sizeof(hints));
    hints.ai_family = AF_INET; // 使用IPv4
    hints.ai_socktype = SOCK_STREAM;

    int status = getaddrinfo(hostname, NULL, &hints, &res);
    if (status != 0) {
        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(status));
        return 1;
    }

    for (ptr = res; ptr != NULL; ptr = ptr->ai_next) {
        struct sockaddr_in *ipv4 = (struct sockaddr_in *)ptr->ai_addr;
        char ipstr[INET_ADDRSTRLEN];
        inet_ntop(AF_INET, &(ipv4->sin_addr), ipstr, INET_ADDRSTRLEN);
        printf("Local IP address: %s\n", ipstr);
    }

    freeaddrinfo(res);
    return 0;
}