#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>

#define PORT 80 
#define MAXDATASIZE 512

char get[128] = "GET \0";

int main(int argc, char *argv[])
{
	int sockfd, numbytes;
	char buf[MAXDATASIZE];
	struct hostent *he;
	struct sockaddr_in their_addr;

	if (argc < 2 || argc > 3)
	{
		fprintf(stderr, "usage: robots <hostname> <path to robots>(if not in root)\n");
		exit(1);
	}

	if (argc == 3)
	{
		strcat(get, argv[2]);
		strcat(get, "/robots.txt\r\n");
	} else {
		strcat(get, "/robots.txt\r\n");
	}

	if ((he = gethostbyname(argv[1])) == NULL)
	{
		herror("gethostbyname");
		exit(1);
	}

	if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
	{
		perror("socket");
		exit(1);
	}

	their_addr.sin_family = AF_INET;
	their_addr.sin_port = htons(PORT);
	their_addr.sin_addr = *((struct in_addr *)he->h_addr);
	memset(&(their_addr.sin_zero), '\0', 8);

	if (connect(sockfd, (struct sockaddr *) &their_addr, sizeof(struct sockaddr)) == -1)
	{
		perror("connect");
		exit(1);
	}

	if (send(sockfd, get, strlen(get), 0) == -1)
         	perror("send");

	while ((numbytes = recv(sockfd, buf, MAXDATASIZE-1, 0) > 0))
	{
		if (numbytes == -1)
		{
			perror("recv");
			exit(1);
		}

		printf("%s", buf);
	}

	printf("\n");

	close(sockfd);

	return 0;
}