리눅스 도메인을 ip주소로 변환하기 쌩초보 도움요청

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <netdb.h>
 
void error_handling(const char* msg) {
        puts(msg);
}
 
int main(void) {
        struct hostent *hostData;
        const char *hnames[] = {"kubernetes.io", "namu.wiki", "filejo.com"};
        struct in_addr address[10];
 
        puts("Call gethostbyname function");
 
        for(int i = 0, j = 0; i < (int)(sizeof(hnames) / sizeof(hnames[0])); i++) {
                hostData = gethostbyname(hnames[i]);
                if(hostData == NULL)
                        error_handling("gethostbyname error!");
                else
                        while(hostData->h_addr != NULL) {
                                address[j] = *(struct in_addr *) hostData->h_addr;
 
                                printf("%s : ", hostData->h_name);
                                printf("%s\n", inet_ntoa(address[j]));
 
                                hostData->h_addr_list++;
                                j++;
                        }
        }
 
        puts("\nCall gethostbyaddr function");
 
        for(int i = 0; i < 10; i++) {
                hostData = gethostbyaddr((const char *)&address[i], sizeof(address[i]), AF_INET);
                printf("%s\n", inet_ntoa(address[i]));
                if(hostData == NULL)
                        error_handling("gethostbyaddr error!");
                else
                        printf("%s\n", hostData->h_name);
        }
 
}