Archive_Tar::_openWrite PHP Method

    function _openWrite()
    {
        if ($this->_compress_type == 'gz') {
            $this->_file = @gzopen($this->_tarname, "wb9");
        } else {
            if ($this->_compress_type == 'bz2') {
                $this->_file = @bzopen($this->_tarname, "w");
            } else {
                if ($this->_compress_type == 'none') {
                    $this->_file = @fopen($this->_tarname, "wb");
                } else {
                    $this->_error('Unknown or missing compression type (' . $this->_compress_type . ')');
                }
            }
        }
        if ($this->_file == 0) {
            $this->_error('Unable to open in write mode \'' . $this->_tarname . '\'');
            return false;
        }
        return true;
    }

 /** Generate a tar/tgz/bz file
  * If you define $installer, this function will also put in
  * the archive a file (si)
  *
  * @param unknown_type $file
  * @param unknown_type $format 
  * @param bool $installer filename for an instaler file
  */
 function generateTarGz($file, $format = 'gz', $installer = null)
 {
     if (!class_exists('Archive_Tar')) {
         include $this->dataDir . '/archive_tar.php';
     }
     $cp = new Archive_Tar($file, $format);
     $v_result = true;
     if (!$cp->_openWrite()) {
         return false;
     }
     foreach ($this->vfsFiles as $n => $v) {
         if (!$cp->_addString(substr($n, 1), $v)) {
             return false;
         }
     }
     $cp->_writeFooter();
     $cp->_close();
     return true;
 }