note 8161 added to ftruncate

I've tested this function and it appears to work correctly with 4.0.1pl2 when a file is open in 'w' mode. Here's my sample code using rewind and ftruncate on a file i've opened and locked. $handle=fopen($filename,"w") or die(); $canwrite = flock($handle,LOCK_EX + LOCK_NB); if ($canwrite) { fputs($handle,"test data xxxxxxx"); rewind($handle); /* Rewind to the top */ fputs($handle,"test"); ftruncate($handle,ftell($handle)); /* Truncate to the current position */ } fclose($handle); // output file will contain "test" only. http://www.php.net/manual/function.ftruncate.php