linux c获取网卡信息

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <arpa/inet.h>

int main() {
    int sockfd;
    struct ifreq ifr;
    struct ifconf ifc;
    char buf[1024];
    int success = 0;

    sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
    if (sockfd == -1) {
        perror("socket");
        return 1;
    }

    ifc.ifc_len = sizeof(buf);
    ifc.ifc_buf = buf;
    if (ioctl(sockfd, SIOCGIFCONF, &ifc) == -1) {
        perror("ioctl(SIOCGIFCONF)");
        return 1;
    }

    struct ifreq* it = ifc.ifc_req;
    const struct ifreq* const end = it + (ifc.ifc_len / sizeof(struct ifreq));

    for (; it != end; ++it) {
        strcpy(ifr.ifr_name, it->ifr_name);
        if (ioctl(sockfd, SIOCGIFFLAGS, &ifr) == 0) {
            if (! (ifr.ifr_flags & IFF_LOOPBACK)) { // don't count loopback
                if (ioctl(sockfd, SIOCGIFHWADDR, &ifr) == 0) {
                    success = 1;
                    break;
                }
            }
        } else {
            perror("ioctl(SIOCGIFFLAGS)");
        }
    }

    if (success) {
        printf("Interface name: %s\n", ifr.ifr_name);
        printf("MAC address: %02x:%02x:%02x:%02x:%02x:%02x\n",
               (unsigned char)ifr.ifr_hwaddr.sa_data[0],
               (unsigned char)ifr.ifr_hwaddr.sa_data[1],
               (unsigned char)ifr.ifr_hwaddr.sa_data[2],
               (unsigned char)ifr.ifr_hwaddr.sa_data[3],
               (unsigned char)ifr.ifr_hwaddr.sa_data[4],
               (unsigned char)ifr.ifr_hwaddr.sa_data[5]);
    }

    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <dirent.h>
#include <string.h>

void list_interfaces() {
    DIR *dir;
    struct dirent *entry;
    char path[256];

    dir = opendir("/sys/class/net");
    if (dir == NULL) {
        perror("opendir");
        return;
    }

    while ((entry = readdir(dir)) != NULL) {
        if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
            continue;

        snprintf(path, sizeof(path), "/sys/class/net/%s/address", entry->d_name);
        FILE *f = fopen(path, "r");
        if (f) {
            char mac[18];
            fgets(mac, sizeof(mac), f);
            printf("Interface: %s, MAC: %s", entry->d_name, mac);
            fclose(f);
        }
    }

    closedir(dir);
}

int main() {
    list_interfaces();
    return 0;
}