网络连通·· [复制链接]

怎么写一个程序判断网络是否连通了？

大侠们，帮忙啊···

int test_link_of_wired_iface(string interface)
{
    const char *iface = interface.c_str();
    int linkup = 0;
    int fdsock = socket(AF_INET, SOCK_DGRAM, 0);
    if(fdsock == -1)
    {
        linkup = 0;
    }
    struct ifreq devifreq;
    struct ifconf ifc;
    char buffer[8192];
    ifc.ifc_len = sizeof(buffer);
    ifc.ifc_buf = buffer;
    strcpy(devifreq.ifr_name, iface);

    if (ioctl(fdsock,SIOCGIFFLAGS,&devifreq) < 0)
        linkup=0;
    if ((devifreq.ifr_flags & IFF_UP)!=0)
    {
        if ((devifreq.ifr_flags & IFF_RUNNING)!=0 )
            linkup=1;
        else
            linkup=0;
    }
    else
        linkup=0;
    close(fdsock);
    return linkup;
}