php实现读取和写入tab分割的文件

//
// save an array as tab seperated text file
//
function write_tabbed_file($filepath, $array, $save_keys=false){
  $content = ;
  reset($array);
  while(list($key, $val) = each($array)){
    // replace tabs in keys and values to [space]
    $key = str_replace("\t", " ", $key);
    $val = str_replace("\t", " ", $val);
    if ($save_keys){ $content .= $key."\t"; }
    // create line:
    $content .= (is_array($val)) ? implode("\t", $val) : $val;
    $content .= "\n";
  }
  if (file_exists($filepath) && !is_writeable($filepath)){ 
    return false;
  }
  if ($fp = fopen($filepath, w+)){
    fwrite($fp, $content);
    fclose($fp);
  }
  else { return false; }
  return true;
}
//
// load a tab seperated text file as array
//
function load_tabbed_file($filepath, $load_keys=false){
  $array = array();
  if (!file_exists($filepath)){ return $array; }
  $content = file($filepath);
  for ($x=0; $x < count($content); $x++){
    if (trim($content[$x]) != ){
      $line = explode("\t", trim($content[$x]));
      if ($load_keys){
        $key = array_shift($line);
        $array[$key] = $line;
      }
      else { $array[] = $line; }
    }
  }
  return $array;
}
/*
** Example usage:
*/
$array = array(
  line1 => array(data-1-1, data-1-2, data-1-3),
  line2 => array(data-2-1, data-2-2, data-2-3),
  line3 => array(data-3-1, data-3-2, data-3-3),
  line4 => foobar,
  line5 => hello world
);
// save the array to the data.txt file:
write_tabbed_file(data.txt, $array, true);
/* the data.txt content looks like this:
line1 data-1-1 data-1-2 data-1-3
line2 data-2-1 data-2-2 data-2-3
line3 data-3-1 data-3-2 data-3-3
line4 foobar
line5 hello world
*/
// load the saved array:
$reloaded_array = load_tabbed_file(data.txt,true);
print_r($reloaded_array);
// returns the array from above