//Lori Walker
//cs290, 11-7-95
//The follwoing program creates an input manipulator called getpass() that rings
//the bell and then prompts for a password.

#include <iostream.h>
#include <string.h>

//A simple input manipulator
  
istream &getpass(istream &stream)
{
  cout << '\a';		//'\a' makes the computer ring internal bell
  cout << "Enter password: ";

  return stream;
}

main()
{
  char pw[80];

  do  {
    cin >> getpass >> pw;
  }  while (strcmp(pw, "password"));
  cout << "Logon complete\n";

  return 0;
}
//Custom manipulators can help to consolidate a sequence of several
//separate I/O operations into one manipulator. It helps to simplify
//your source code and prevent unwanted errors.
//An input manipulator receives a reference to the stream for which it was    
//invoked.  This stream must be returned by the manipulator.
//It is crucial that your manipulators return stream. If not, your manipulator
//cannot be used in a compound input or output expression.
//The manipulator I have chosen is called &getpass (&reference) which is
//supposed to ring the bell then prompt the user for a password.  After which
//it runs through a 'while' loop to do a string compare for the proper
//password, and won't let you access until it is given correctly. Then outputs
//to the screen "logon complete".  A simple use of an istream.