Unit Aerolineas

unit Aerolineas;
interface
uses crt;
type
    t_aerolinea=record
                      cod:string[10];
                      nombre:string[40];
                      cuit:integer;
                      domicilio:string[30];
                      activo:boolean;
                      end;
    aerolinea= file of t_aerolinea;

var aer:aerolinea; reg:t_aerolinea; pos:integer;

procedure abrir (var aer:aerolinea);
procedure leer (var aer:aerolinea; pos:integer; var reg:t_aerolinea);
procedure guardar (var aer:aerolinea; reg:t_aerolinea);
procedure modificar (var aer:aerolinea; pos:integer; reg:t_aerolinea);


implementation
procedure abrir (var aer:aerolinea);
begin
     assign ('Aerolineas.dat',aer);
     reset (aer);
     if ioresult <> 0 then
        rewrite (aer);
end;

procedure leer (var aer:aerolinea; pos:integer; var reg:t_aerolinea);
begin
     seek (aer,pos);
     read (aer,reg);
end;
procedure guardar (var aer:aerolinea; reg:t_aerolinea);
begin
     seek (aer, filesize (aer));
     write (aer,reg);
end;
procedure modificar (var aer:aerolinea; pos:integer; reg:t_aerolinea);
begin
     seek (aer,pos);
     write (aer,reg);
end;
begin

end.