the magics of eof()

17 Dec 2004

      Dear friends,

I don't know if what I found is a bug or a correct behaviour I don't 
understand.

The following  program halts with error 'attempt ro read past end of file';

program test;
var
  f : file of char;
begin
  rewrite(f,'test.dat');
  seek(f,0);
  f^:='x'; (*GIVES ERROR HERE*)
  put(f);
  close(f);
end.

If I just insert a call reading eof(f) everything seems to work:

program test;
var
  f : file of char;
begin
  rewrite(f,'test.dat');
  seek(f,0);
  if eof(f) then ;   (* do nothing *)
  f^:='x';
  put(f);
  close(f);
end.

I am puzzled!

(working with gpc 20030830)

Ciao,
Francesco

the magics of eof()

Francesco Bonomi