The fdf_open_string() function reads form data from a string. fdf_data must contain the data as returned from a PDF form or created using fdf_create() and fdf_save_string().
You can fdf_open_string() together with $HTTP_FDF_DATA to process fdf form input from a remote client.
See also fdf_open(), fdf_close(), fdf_create() and fdf_save_string().