Pascal. Unidirectional list. Loop

Question

Here is an example program from a book. I can't stop the "while not eof" loop. I tried to insert in program "Uses crt;", "const CheckEof: boolean=true" and to press "ctrl+Z" while running, it doesn't work.

Program P123;
uses 
  crt; {My insertion}

type 
   Adresacelula = ^Celula;

   Celula = record
     Info: string;
     Urm: AdresaCelula;
   end;

var 
  P, Q, R: AdresaCelula;
  s: string;
  i: integer;

const 
  CheckEOF: boolean = true; {My insertion}

  Procedure Create;
  begin
    p := nil;
    write ('s='); readln (s);
    new (r); r^.Info := s; r^.Urm := nil;
    p := r; q := r;
    write ('s=');
       
    while not eof do {Here is the loop i need to stop}
    begin
      readln (s); write ('s=');
      new (r); r^.Info := s; r^.Urm := nil;
      q^.Urm := r; q := r;
    end;
  end;

  Procedure Display;
  begin
    r := p;

     while r<>nil do
     begin
       writeln (r^.Info);
       r := r^.Urm;
     end;

     readln;
   end;

 begin
   Create;
   Display;

 end.

Answer 1

To make the example work, remove the line

const CheckEOF: boolean=true; {My insertion}

and insert CheckEOF:=true; before the Create; call in the main program. Then the program terminates when you press Ctrl-Z.

Your code declares a new variable CheckEOF while you probably want to change CheckEOF of the crt unit.