//================================================= file = udpErrorDemo.c =====
//=  A sockets program to demonstrate WSAGetLastError() for Winsock           =
//=============================================================================
//=  Notes:                                                                   =
//=    1) This program compiles only for Winsock                              =
//=    2) This program does an incorrect socket call and then returns an      =
//=       error.                                                              =
//=    3) Socket error codes can be found on MSDN:                            =
//=         - http://msdn.microsoft.com/en-us/library/windows/desktop/        =
//=           ms740668(v=vs.85).aspx                                          =
//=---------------------------------------------------------------------------=
//=  Example execution:                                                       =
//=    *** ERROR - bind() failed with WSA error = 10038                       =
//=---------------------------------------------------------------------------=
//=  Build: bcc32 udpErrorDemo.c or cl udpErrorDemo.c wsock32.lib for Winsock =
//=---------------------------------------------------------------------------=
//=  Execute: udpErrorDemo                                                    =
//=---------------------------------------------------------------------------=
//=  Author: Ken Christensen                                                  =
//=          University of South Florida                                      =
//=          WWW: http://www.csee.usf.edu/~christen                           =
//=          Email: christen@csee.usf.edu                                     =
//=---------------------------------------------------------------------------=
//=  History:  KJC (09/19/14) - Genesis (from udpServer.c)                    =
//=============================================================================

//----- Include files ---------------------------------------------------------
#include <stdio.h>          // Needed for printf()
#include <string.h>         // Needed for memcpy() and strcpy()
#include <stdlib.h>         // Needed for exit()
#include <windows.h>        // Needed for all Winsock stuff

//----- Defines ---------------------------------------------------------------
#define  PORT_NUM   1050    // Arbitrary port number for the server

//===== Main program ==========================================================
int main()
{
  WORD wVersionRequested = MAKEWORD(1,1);       // Stuff for WSA functions
  WSADATA wsaData;                              // Stuff for WSA functions
  int                  server_s;        // Server socket descriptor
  struct sockaddr_in   server_addr;     // Server Internet address
  struct sockaddr_in   client_addr;     // Client Internet address
  struct in_addr       client_ip_addr;  // Client IP address
  int                  addr_len;        // Internet address length
  int                  retcode;         // Return code

  // This stuff initializes winsock
  WSAStartup(wVersionRequested, &wsaData);

  // Create a socket
  server_s = socket(AF_INET, SOCK_DGRAM, 0);
  if (server_s < 0)
  {
    printf("*** ERROR - socket() failed with WSA error = %d \n",
      WSAGetLastError());
    exit(-1);
  }

  // Create an error condition...
  server_s = 0;

  // Fill-in my socket's address information
  server_addr.sin_family = AF_INET;                 // Address family to use
  server_addr.sin_port = htons(PORT_NUM);           // Port number to use
  server_addr.sin_addr.s_addr = htonl(INADDR_ANY);  // Listen on any IP address
  retcode = bind(server_s, (struct sockaddr *)&server_addr,
    sizeof(server_addr));
  if (retcode < 0)
  {
    printf("*** ERROR - bind() failed with WSA error = %d \n",
      WSAGetLastError());
    exit(-1);
  }

  // Close all open sockets
  retcode = closesocket(server_s);
  if (retcode < 0)
  {
    printf("*** ERROR - closesocket() failed with WSA error = %d \n",
      WSAGetLastError());
    exit(-1);
  }

  // This stuff cleans-up winsock
  WSACleanup();

  // Return zero and terminate
  return(0);
}