/*
A small example program to demonstrate converting among
	textual representation of hostname
	dotted decimal representation
 */
 
#include <stdio.h>
#include <stdlib.h> 	// calloc
#include <string.h>		// memset, strncpy
#include <netdb.h>		// hostent, gethostbyname
#include <sys/types.h>	// inet_ntop
#include <sys/socket.h>	// inet_ntop
#include <arpa/inet.h>	// inet_ntop
#include <unistd.h>		// close

#define SIZE_MAX 31

 int main (int argc, char* argv[]) {

	int i;
	char *hostname;
	char **pptr;
	char ipadd[INET_ADDRSTRLEN];
	struct hostent *hptr;

	struct sockaddr_in servaddr;
	int sockfd;

	char buf[20];
 
	if (argc != 2) {
		printf("Usage: <prog_name> <hostname>\n");
		return 1;
	}

	/**************** PART 1 ***********************/
	hostname = calloc(SIZE_MAX, sizeof(char));
	memset(hostname, '\0', SIZE_MAX);
	strncpy(hostname, argv[1], strlen(argv[1]));
	
	printf("\tHostname received from user = %s\n\n", hostname);

	if ( (hptr = gethostbyname(hostname)) == NULL) {
			// gethostbyname sets the h_errno value, not the errno
			printf("gethostbyname error : %s\n", hstrerror(h_errno));
			return 1;
	}

	printf("\tOfficial hostname = %s\n", hptr->h_name);

	for (pptr = hptr->h_aliases; *pptr != NULL; pptr++) 
		printf("\tAlias = %s\n", *pptr);

	if (hptr->h_addrtype == AF_INET) {
		for (pptr = hptr->h_addr_list; *pptr != NULL; pptr++) {
			
			// *pptr does not end with '\0' 
			//printf("\tDotted decimal(weird!) = %s\n", *pptr);

			inet_ntop(AF_INET, *pptr, ipadd, INET_ADDRSTRLEN);
			printf("\tDotted decimal = %s\n", ipadd);
		}
	}


	/**************** PART 2 ***********************/
	if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("socket");
		return 1;
	}

	memset(&servaddr, '\0', sizeof(servaddr));
	servaddr.sin_port = htons(3346); // connect to port 
	inet_pton(AF_INET, ipadd, &servaddr.sin_addr);

	if ( (i = connect (sockfd, (struct sockaddr*) &servaddr, 
									sizeof(servaddr))) < 0) {
		perror("Could not connect to port 80");
		return 1;
	}

	printf("\tConnected.\n");

	i = 0;
	i = send(sockfd, "hi", 2, 0);
	printf("\tSent %d.\n", i);

	recv(sockfd, buf, 10, 0);
	printf("buf = %s\n", buf);

	//close(sockfd);

	
	return 0;
} // end of main