#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <string>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <errno.h>
#include <unistd.h>
#include <iostream>
#include <sstream>
#include <vector>
#include <algorithm>
#include <signal.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <signal.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <fcntl.h>
using namespace std;

int main(int argc, char * argv[])
{
  int sockfd, res;
  int clientfd;
  struct sockaddr_in dest;
  char buffer[3] = "% ", buffer1[65535];
  char welcome[500] = "****************************************\n** Welcome to the information server. **\n****************************************\n% ";
  pid_t child;
  socklen_t clilent;
  setvbuf(stdout, NULL, _IONBF, 0);
  bzero(&dest, sizeof(dest));
  dest.sin_family = AF_INET;
  dest.sin_port = htons(5432);
  dest.sin_addr.s_addr = INADDR_ANY;
  sockfd = socket(PF_INET, SOCK_STREAM, 0);
	
  if(sockfd < 0)
  {
	perror("Socket Error");
	exit(-1);
  }
	
  if(bind(sockfd, (struct sockaddr*)&dest, sizeof(dest)) < 0)
  {
	perror("Bind Error");
	close(sockfd);
	exit(-1);
  }	
	
  if(listen(sockfd, 1) < 0)
  {
	perror("Listen Error");
	close(sockfd);
	exit(-1);
   }	

    while(1)
    {
        struct sockaddr_in client_addr;
        int addrlen = sizeof(client_addr);
		
        /*Accept*/
        if(clientfd = accept(sockfd, (struct sockaddr *)&client_addr, (socklen_t*)&addrlen) < 0)
		{
			perror("Accpet Error");
			close(sockfd);
			exit(-1);
		}
		
		/*Fork process*/
		if(child = fork() < 0)
		{
			perror("Fork Error");
			close(sockfd);
			exit(-1);
		}
		else if(child == 0)
		{
			int my_client = clientfd;
			close(sockfd);
			
			send(my_client, welcome, sizeof(welcome), 0);

			while ((res = recv(my_client, buffer1, sizeof(buffer1), 0)) > 0)
			{
				string command(buffer1);
				cout << "receive from client:" << command << ", " << res << " bytes\n";
				memset(buffer1, '\0', sizeof(buffer1));		
			}
		}
		
		close(clientfd);
			
   } 
   
	return 0;
}