csv - PHP file writing - 0x00 appearing in files -

i have written php program compiles csv child , grandchild csvs later use. however, in files keep getting null bytes in same place. when writing same string different file problem disappears. i've tried can think of , cannot find source of bug. has come bug before?

here code:

error_reporting(e_all); $handles=array();  function get_handle($file) {  global $handles;  $file=unsafe($file);   foreach($handles $key=>$value) {   if($key==$file) return $value;  }   $handle=fopen($file, "w+b");  $handles[$file]=$handle;  return $handle; }  function safe($str) {  return str_replace(array(',', "\r", "\n", '#', '-'), array('%2c', '%0d', '%0a', '%23', '%2d'), trim(trim($str), "\0")); }  function additional_format($str) {  return $str; }  function unsafe($str) {  return str_replace(array('%2c', '%0d', '%0a', '%23', '%2d'), array(',', "\r", "\n", '#', '-'), $str); }  $titles=array('server', 'condition', 'vehicle', 'make', 'model'); $fhandle=fopen("input.csv", "r");  while($frow=safe(fgets($fhandle))) {  if(substr($frow, 0, 7)!='http://') continue;  $url=array_map('safe', explode('/', substr($frow, 7)));  $additional=array_map('safe', array_slice($url, 5));  $additional_string=implode(" ", $additional);  $url=array_combine($titles, array_slice($url, 0, 5));  $make=get_handle($url['make'].".csv");  fwrite($make, ucwords($url['model'])."\r\n");  fflush($make);  $variation_types=array();   for($addi=0;isset($additional[$addi])&&!empty($additional[$addi]);$addi+=2) {    if(!isset($variation_types[$additional[$addi]])) {    $variation_types[$additional[$addi]]=array();   }    if(!in_array($additional[$addi+1], $variation_types[$additional[$addi]])) {    array_push($variation_types[$additional[$addi]], $additional[$addi+1]);   }    $variation_file=get_handle($url['make'].'-'.$url['model'].'-'.$additional[$addi].'-'.$additional[$addi+1].".csv");   fwrite(    $variation_file,    trim($frow, ',').",".strtolower($url['model']." ".$additional_string."\r\n")   );   fflush($variation_file);   if(1) fwrite(get_handle("test.csv"), trim($frow, ',').",".$url['model']." ".$additional_string."\r\n");  }    $model=get_handle($url['make'].'-'.$url['model'].".csv");  foreach($variation_types $type=>$variations) {   fwrite($model, $type.','.implode(',', $variations)."\r\n");   fflush($model);  }  } 

a sample input csv (the real files larger):

http://server/used/cars/ford/capri/trim/cc-2 http://server/used/cars/ford/capri/engine/2.0 http://server/used/cars/ford/capri/fuel/petrol http://server/used/cars/ford/capri/transmission/manual http://server/used/cars/ford/capri/colour/black http://server/used/cars/ford/capri/colour/blue http://server/used/cars/ford/capri/colour/gold http://server/used/cars/ford/capri/colour/purple http://server/used/cars/ford/capri/colour/red http://server/used/cars/ford/capri/colour/silver 

and input in format (-, #, comma, \r , \n urlencoded) end like:

http:/server/used/cars/ford/capri/colour/black,capri colour black ##0x00 times 2549##http://server/used/cars/ford/capri/trim/cc%2d2/colour/black/door/2,capri trim cc%2d2 colour black door 2 http://server/used/cars/ford/capri/bodystyle/convertible/colour/black/door/2,capri bodystyle convertible colour black door 2 http://server/used/cars/ford/capri/engine/2.0/colour/black/door/2,capri engine 2.0 colour black door 2 http://server/used/cars/ford/capri/fuel/petrol/colour/black/door/2,capri fuel petrol colour black door 2 http://server/used/cars/ford/capri/transmission/manual/colour/black/door/2,capri transmission manual colour black door 2 

thanks in advance

[edit] record, removing trim($str, "\0") makes no difference , php version 5.3.1 (cli)

never mind, ive (well else) has solved it. because of windows file case-insensitivity... had handles ford-capri-colour-black.csv , ford-capri-colour-black.csv colliding. windows 8-)