/* A simple server in the internet domain using TCP
   The port number is passed as an argument */
/* code from: http://www.cs.rpi.edu/~moorthy/Courses/os98/Pgms/socket.html */
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <unistd.h>
#include <netinet/in.h>

void
error(char *msg)
{
	perror(msg);
	exit(1);
}

int
main(int argc, char *argv[])
{
	int                sockfd, newsockfd, portno, clilen;
	char               buffer[256];
	struct sockaddr_in serv_addr, cli_addr;
	int                n;
	if (argc < 2) {
		fprintf(stderr, "ERROR, no port provided\n");
		exit(1);
	}
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) error("ERROR opening socket");
	bzero((char *)&serv_addr, sizeof(serv_addr));
	portno                    = atoi(argv[1]);
	serv_addr.sin_family      = AF_INET;
	serv_addr.sin_addr.s_addr = INADDR_ANY;
	serv_addr.sin_port        = htons(portno);
	if (bind(sockfd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) error("ERROR on binding");
	listen(sockfd, 5);
	clilen    = sizeof(cli_addr);
	newsockfd = accept(sockfd, (struct sockaddr *)&cli_addr, &clilen);
	if (newsockfd < 0) error("ERROR on accept");
	bzero(buffer, 256);
	n = recv(newsockfd, buffer, 255, 0);
	if (n < 0) error("ERROR reading from socket");
	printf("Here is the message: %s\n", buffer);
	n = send(newsockfd, "I got your message", 18, 0);
	if (n < 0) error("ERROR writing to socket");
	close(newsockfd);
	close(sockfd);

	return 0;
}