C++ gethostbyname error No such file or directory

Question

I use arm ld-linux-armhf.so.3 excute program on aarch system. When I call gethostbyname failed with No such file or directory

char host[100] = "www.google.com";
struct hostent *hp;
if ((hp=gethostbyname(host)) == NULL){
    cout<<"gethostbyname\t"<<-2<<endl;
    if(errno!=0)
    {
        cout<<"gethostbyname\t"<<errno<<endl;
        cout<<"gethostbyname\t"<<strerror(errno)<<endl;
    }
}

Print

gethostbyname   -2
gethostbyname   2
gethostbyname   No such file or directory

/etc/resolve.conf

nameserver 8.8.8.8

/etc/hosts

127.0.0.1   localhost
127.0.0.1 AIBox
1.1.1.1 www.google.com

How do I know which file is not found?

Changed to h_errno.

char host[100] = "www.google.com";
struct hostent *hp;
if ((hp=gethostbyname(host)) == NULL){
    cout<<"gethostbyname\t"<<-2<<endl;
    if(errno!=0)
    {
        cout<<"gethostbyname\t"<<h_errno<<endl;
        cout<<"gethostbyname\t"<<hstrerror(h_errno)<<endl;
    }
}

Print

gethostbyname   -2
gethostbyname   3
gethostbyname   Unknown server error