/***********************************************************
 * Server developed in class.
 * This server just changes lower case letters to capitals.
 * It always listens on port 10000.
 ***********************************************************/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

int main()
{
  /* Set up socket */
  int sfd = socket(AF_INET,SOCK_STREAM,0);
  if (sfd == -1) { fprintf(stderr,"Socket not created!\n"); exit(1); }

  /* Hardcoded IP address and port number. */
  unsigned int  ipnum = 2205833693U; /* The "U" makes this an usigned int literal */
  unsigned short pnum = 10000;

  /* Set up address structure */
  struct sockaddr_in mysa;
  mysa.sin_family = AF_INET;
  mysa.sin_addr.s_addr = htonl(ipnum);
  mysa.sin_port = htons(pnum);

  /* Bind socket to address */
  if (bind(sfd,(struct sockaddr*)&mysa,sizeof(mysa)) < 0)
  {
    close(sfd);
    fprintf(stderr,"bind failed!\n");
    exit(3);
  }

  /* Listen for connection request */
  if (listen(sfd,20) < 0)
  {
    close(sfd);
    fprintf(stderr,"listen failed!\n");
    exit(4);    
  }

  /* Accept the connection request */
  int sessionfd = accept(sfd,NULL,NULL);
  if (sessionfd == -1)
  { 
    close(sfd);
    fprintf(stderr,"accept failed!\n");
    exit(5);    
  }   

  /* Serve this connection. */
  char inc, outc;
  while(read(sessionfd,&inc,1) == 1)
  {
    if ('a' <= inc && inc <= 'z')
      outc = inc - 'a' + 'A';
    else
      outc = inc;
    write(sessionfd,&outc,1);
  }      
  close(sessionfd);

  fprintf(stderr,"Server shutting down!\n");
  close(sfd);
  return 0;
}