I hope this is not OT. I am trying to learn to use CFFI. Following the CFFI manual, I wrote the following functions, which call some basic C time functions. According to gmtime(3), the function `gmtoff' below should always return 0. However, I consistently get

TIMEZONE-FFI> (gmtoff) 672421260

I would appreciate any hints as to where I am erring. In case it is relevant, the environment is CMUCL 19c on FreeBSD 6.0-STABLE.

TIA, Raghavendra.

--- code follows ---

(defpackage #:timezone-ffi (:use #:common-lisp #:cffi))

(in-package #:timezone-ffi)

(defcstruct tm (sec :int) (min :int) (hour :int) (mday :int) (mon :int) (year :int) (wday :int) (yday :int) (isdst :boolean) (zone :string) (gmtoff :long))

(defctype time :int)

(defcfun ("time" %time) time (tp :pointer))

(defcfun (gmtime %gmtime) :pointer (tp :pointer))

;; Should return 0 always. (defun gmtoff () (with-foreign-object (tp 'time) (setf (mem-ref tp 'time) (%time (null-pointer))) (foreign-slot-value (%gmtime tp) 'tm 'gmtoff)))