/* hostinfo.c
 *
 * from CMU's Computer Systems text
 *    http://csapp.cs.cmu.edu/3e/ics3/code/netp/hostinfo.c
 * requires csapp.c, csapp.h
 *
 *   $ gcc -O2 -pthread hostinfo.c csapp.c -o hostinfo
 *   $ ./hostinfo cs.bennington.college
 *   96.126.108.24
 */

#include "csapp.h"

int main(int argc, char **argv){
    struct addrinfo *p, *listp, hints;
    char buf[MAXLINE];
    int rc, flags;

    if (argc != 2) {
	fprintf(stderr, "usage: %s <domain name>\n", argv[0]);
	exit(0);
    }

    /* Get a list of addrinfo records */
    memset(&hints, 0, sizeof(struct addrinfo));                         
    hints.ai_family = AF_INET;       /* IPv4 only */
    hints.ai_socktype = SOCK_STREAM; /* Connections only */
    if ((rc = getaddrinfo(argv[1], NULL, &hints, &listp)) != 0) {
        fprintf(stderr, "getaddrinfo error: %s\n", gai_strerror(rc));
        exit(1);
    }

    /* Walk the list and display each IP address */
    flags = NI_NUMERICHOST;   /* Display address string instead of domain name */
    for (p = listp; p; p = p->ai_next) {
        Getnameinfo(p->ai_addr, p->ai_addrlen, buf, MAXLINE, NULL, 0, flags);
        printf("%s\n", buf);
    } 

    /* Clean up */
    Freeaddrinfo(listp);

    exit(0);
}