note 11658 added to fopen

When you want that data is write at the begin of the file and don't want that its overwrite the existing data, how do you do that? example: file post.dat white the text abc. You want to ad a 'd'. The white $fh = fopen(post.dat, r+); fputs($fh, d); in the file wile come now dbc and it needs to be dabc. Thanx http://www.php.net/manual/nl/function.fopen.php