We will first create an object ppufile which will be used below. We are opening unit test.ppu as an example.
uses ppu;
{$mode objfpc}
var
ppufile : tppufile;
begin
{ Initialize object }
ppufile:=tppufile.create('test.ppu');
{ open the unit and read the header, returns false when it fails }
if not ppufile.openfile then
Writeln('error opening unit test.ppu');
{ here we can read the unit }
{ close unit }
ppufile.closefile;
{ release object }
ppufile.free;
end.
Note: When a function fails (for example not enough bytes left in an entry) it sets the ppufile.error variable.