Virtual Pascal for OS/2 v1.00
  (C) 1996 fPrint UK Ltd
  London, 7 April 1996


  The Os2Exec unit
  ~~~~~~~~~~~~~~~~
  The Os2Exec unit implements a VP/2 class, TRedirExec, which allows your
  programs to capture the output of a child process which outputs text to
  standard output.

  To demonstrate the use of the class, an example program TRedirExec has
  been included.  It creates a TRedirExec instance, and executes a DIR
  command (through the CMD.EXE command processor) 5 times, and displays
  the output in a window on the screen by using the Window procedure of
  the Crt window.


  TRedirExec
  ~~~~~~~~~~
  The TRedirExec class implements the following published fields, which
  can be used by application programs.

  constructor create        Must be called to create instance
  destructor Destroy        Must be called to free instance

  function Execute          Is called to execute a child process.
                            Returns True, if the process was executed
                            succesfully, and False otherwise.

  property Terminated       Returns True, if the executing process has
                            terminated and no further lines of output
                            are available.

  property MessageReady     Returns True, if a line of output from the
                            child process is ready.

  property ReturnCode       When Terminated returns True, this property
                            contains the return code of the process.

  property Message          Returns any available output string from the
                            child process, or a blank line if no message
                            is ready.

  property OnTerminate      This method is called when the process terminates

  property OnCharReady      This method is called every time a character is
                            received from the child process.  Can be used to
                            perform any pre-processing required.

  property OnLineReady      This method is called every time a line is
                            received.

  Do note, that the methods are called only when the main program checks
  the state of MessageReady or Message.