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

#define MAXLINE 4096 /*max text line length*/
#define SERV_PORT 3000 /*port*/
#define LISTENQ 8 /*maximum number of client connections */

int main (int argc, char **argv)
{
 int listenfd, n;
 socklen_t len;
 char buf[MAXLINE];
 struct sockaddr_in cliaddr, servaddr;
	
 //creation of the socket
 listenfd = socket (AF_INET, SOCK_DGRAM, 0);
	
 //preparation of the socket address 
 servaddr.sin_family = AF_INET;
 servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
 servaddr.sin_port = htons(SERV_PORT);
	
 bind(listenfd, (struct sockaddr *) &servaddr, sizeof(servaddr));
	
 for ( ; ; ) {
		
  len = sizeof(cliaddr);
  n = recvfrom(listenfd, buf, MAXLINE,0, ( struct sockaddr *)&cliaddr,&len);	
  if (n < 0) {
   perror("Read error"); 
   exit(1);
  }
  buf[n] = '\0';
  printf("%s","String received from and resent to the client: ");
  fputs(buf, stdout);
  sendto(listenfd, buf, n, 0, ( struct sockaddr *)&cliaddr, sizeof(cliaddr));
 }
		
 close(listenfd);
	
}