Date   : Thu, 14 Feb 1985 09:28:13 EST (Thursday)
From   : Bob <Slomcenski.wbst@XEROX.ARPA>
Subject: Re: Problem reading while not eoln in Turbo Pascal

Dave,
  One alternative to the character - read problem that I have used (I
use Turbo on an 8 bit Z80 -CP/M system) is the following:
  
  { Function InKey - Returns a keystroke from the keyboard }
  { returns a keyboard character if one is present, else returns ASCII
NUL }

  function InKey: char;
      var  ch: char;
      begin
        if KeyPressed then Read(Kbd,ch) else ch:= chr(0);
        InKey:= ch;
      end;

  Using this procedure, you can get (and process) any keystroke from the
keyboard. You must provide the explicit processing for the character,
ie: you can't use eoln.
  
  This function emulates the BASIC INKEY$ function that is available in
most of the BASICs now in use. It does not echo to the CRT, and if no
key has been pressed, it returns ASCII NUL.
  
  I would use it in your code as follows:
  
>   var
>        Index: integer;
>        InChar: char;
>        Digits: array [1..5] of integer;
> 
>   begin
>        { lines to request user input }
>        Index:= 0;
>        InChar:= #0;
>              while ((Index < 5) and (InChar <> #13)
>                do begin
>                  InChar:= InKey;
>              case InChar of
>                #0, #13: begin end;
>                '0'..'7': begin
>                                Index:= Index + 1;
>                                Digits[Index]:= (ord(InChar) -
ord('0'));
>                            write(InChar); { echo character }
>                              end;
>                otherwise: begin
>                               { invalid character routine }
>                               end;
>                end; { while }
> 

~ Bob