/*
 * selfid.c -- identify attributes of current host
 */

#include   <sys/types.h>
#include   <sys/socket.h>
#include   <sys/param.h>
#include   <netinet/in.h>
#include   <netdb.h>

int main()
{
	int    sockfd;
	char   hostname[MAXHOSTNAMELEN+1];
	struct sockaddr_in saddr;
	int    slen = sizeof(struct sockaddr_in);
        struct hostent  *hp;
        char   **p;

	if (gethostname(hostname, MAXHOSTNAMELEN) < 0) {
           perror("gethostname"); exit(1);}
	printf ("Hostname (from gethostname) = %s\n", hostname);

        if ((hp = gethostbyname(hostname)) == NULL) {
           perror("gethostbyname"); exit(1);}
        printf("Official Name (from gethostbyname) = %s\n", hp->h_name);
        p = hp->h_aliases;
        while (*p) {
            printf("ALIAS = %s\n", *p); p++;}
	printf("addrtype = %d\n", hp->h_addrtype);
        printf("length of address = %d\n", hp->h_length);
	p = hp->h_addr_list;
	while (*p) {
	  printf("IP according to gethostbyname = %s\n", inet_ntoa(*p)); p++;}

	if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
	  perror("socket"); exit(1);}

	bzero((char *)&saddr, sizeof(saddr));
        saddr.sin_family = hp->h_addrtype;
        saddr.sin_port = htons(0);
        saddr.sin_addr.s_addr = htonl(INADDR_ANY);
        if (bind(sockfd, (struct sockaddr *)&saddr, sizeof(saddr)) < 0) {
	  perror("bind"); exit(1);}

	if (getsockname(sockfd, &saddr, &slen) < 0) {
	  perror("getsockname"); exit(1);}
	printf("Socket Family = %u\n", ntohs(saddr.sin_family));
	printf("Port = %u\n", ntohs(saddr.sin_port));
        printf("IP = %s\n", inet_ntoa(saddr.sin_addr.s_addr));	
	exit(0);
}