(PHP 4, PHP 5)
fdf_save — Save a FDF document
$fdf_document
[, string $filename
] )Saves a FDF document.
fdf_document
The FDF document handle, returned by fdf_create(), fdf_open() or fdf_open_string().
filename
If provided, the resulting FDF will be written in this parameter. Otherwise, this function will write the FDF to the default PHP output stream.
成功时返回 TRUE， 或者在失败时返回 FALSE。