/* server process */
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <signal.h>
#define SIZE sizeof(struct sockaddr_in)
#define NULL 0
void catcher(int sig);
int newsockfd;

main(){
  int sockfd;
  char c;
  struct sockaddr_in server = {AF_INET, 7001, INADDR_ANY};

  static struct sigaction act;
  act.sa_handler = catcher;
  sigfillset(&(act.sa_mask));
  sigaction(SIGPIPE, &act, 0);
/* set up the transport end point */
  if ( (sockfd = socket(AF_INET, SOCK_STREAM, NULL)) == -1){
    perror("socket call failed");
    exit(1);
  }
/* bind an address to the end point */
  if ( bind(sockfd, (struct sockaddr *)&server, SIZE) == -1){
    perror("bind call failed");
    exit(1);
  }
/* start listening for incoming connections */
  if ( listen(sockfd, 0) == -1 ){
    perror("listen call failed");
    exit(1);
  }
  for (;;){
/* accept a connection */
    if ( (newsockfd = accept(sockfd, NULL, NULL))== -1){
      perror("accept call failed");
      continue;
    }
/* spawn a child to deal with the connection */
    if ( fork() == 0){
      while (recv(newsockfd, &c, 1, 0) > 0){
        c = toupper(c);
	printf("%c",c);
        send(newsockfd, &c,1, 0);
      }
/* when client is no longer sending information the socket can be closed 
   and the child process terminated */
    close(newsockfd);
    exit (0);
    close(newsockfd);
    exit(0);
    }
/* parent doesn't need the newsockfd */
    close(newsockfd);
  }
}   
void catcher(int sig){
close(newsockfd);
exit (0);
}