l dfftw_import_system_wisdom(isuccess)
</pre>
   <p>As usual, the C return value is turned into a first parameter;
<code>isuccess</code> is non-zero on success and zero on failure (e.g. if
there is no system wisdom installed).

   <p>If you want to import/export wisdom from/to an arbitrary file or
elsewhere, you can employ the generic <code>dfftw_import_wisdom</code> and
<code>dfftw_export_wisdom</code> functions, for which you must supply a
subroutine to read/write one character at a time.  The FFTW packag