The configure script supports both the directory structure of the FDF SDK distribution and the usual DIR / include / DIR / lib layout, so you can point it either directly to the unpacked distribution directory or put the header file and the appropriate library for your platform into e.g. / usr / local / include and / usr / local / lib and configure with --with-fdftk= / usr / local.
If you look at an FDF-document with a text editor you will find a catalogue object with the name FDF. Such an object may contain a number of entries like Fields, F, Status etc.. The most commonly used entries are Fields whicht points to a list of input fields, and F which contains the filename of the PDF-document this data belongs to. Those entries are referred to in the FDF documention as /F-Key or /Status-Key. Modifying this entries is done by functions like fdf_set_file() and fdf_set_status(). Fields are modified with fdf_set_value(), fdf_set_opt() etc..