gethostbyname_r、gethostbyaddr_r
#include<unistd.h>
#include<netdb.h>
int main()
{
struct hostent hostbuf,*res = NULL;
char buf[8192] = {0};
int err = 0;
//gethostbyname_r("www.baidu.com",&hostbuf,buf,sizeof(buf),&res,&err);
in_addr_t addr = inet_addr("127.0.0.1");
gethostbyaddr_r((char*)&addr,4,AF_INET,&hostbuf,buf,sizeof(buf),&res,&err);
printf("h_name:%s\n",res->h_name);
return 0;
}