Save a FDF document (PHP 3 >= 3.0.6, PHP 4, PHP 5)
bool fdf_save ( resource fdf_document [, string filename] )

The fdf_save() function saves a FDF document. The resulting FDF will be written to filename. Without a filename fdf_save() will write the FDF to the default PHP output stream.

See also fdf_save_string(), fdf_create() and fdf_close().