int fftw_import_system_wisdom(void);
int fftw_import_wisdom_from_filename(const char *filename);
int fftw_import_wisdom_from_string(const char *input_string);
int fftw_import_wisdom(int (*read_char)(void *), void *data);
These functions import wisdom into a program from data stored by the
fftw_export_wisdom functions above. (See Words of Wisdom-Saving Plans.) The imported wisdom replaces any wisdom
already accumulated by the running program.
fftw_import_wisdom imports wisdom from any input medium, as
specified by the callback function read_char. read_char is
a getc-like function that returns the next character in the
input; its parameter is the data pointer passed to
fftw_import_wisdom. If the end of the input data is reached
(which should never happen for valid data), read_char should
return EOF (as defined in <stdio.h>). For convenience,
the following three “wrapper” routines are provided:
fftw_import_wisdom_from_filename reads wisdom from a file named
filename. A lower-level function, which requires you to open
and close the file yourself (e.g. if you want to read wisdom from a
portion of a larger file) is fftw_import_wisdom_from_file. This
reads wisdom from the current position in input_file (which
should be open with read permission); upon exit, the file remains
open, but the position of the read pointer is unspecified.
fftw_import_wisdom_from_string reads wisdom from the
NULL-terminated string input_string.
fftw_import_system_wisdom reads wisdom from an
implementation-defined standard file (/etc/fftw/wisdom on Unix
and GNU systems).
The return value of these import routines is 1 if the wisdom was
read successfully and 0 otherwise. Note that, in all of these
functions, any data in the input stream past the end of the wisdom data
is simply ignored.