src/library.lisp

   1 (in-package :sane)
   2
   3 (define-foreign-library libsane
   4     (:unix (:or "libsane.so.1" "libsane.so"))
   5     (t (:default "libsane")))
   6
   7 (defun sane-interpret-version (n)
   8   "Read bitstring for version and output the correct major/minor/rev
   9 version"
  10   (list
  11    (ash n -24)                          ; major
  12    (boole boole-and (ash n -16) 255)    ; minor
  13    (boole boole-and n 65535)))
  14
  15 (defmacro with-init (version-sym &body body)
  16   "Run BODY with VERSION-SYM set to a triple representing the version of libsane
  17 that is running. Evaluates to BODY. If VERSION-SYM is nil, there is no symbol
  18 bound to the version."
  19   (let ((c-version (gensym)))
  20
  21     `(unwind-protect
  22           (with-foreign-object (,c-version :int)
  23             (use-foreign-library libsane)
  24             (sane-lowlevel:ensure-ok
  25              (sane-lowlevel::sane_init ,c-version (null-pointer))
  26              "Failed to initialise sanelib.")
  27
  28             (let ,(when version-sym
  29                         `((,version-sym (sane-interpret-version
  30                                          (mem-ref ,c-version :int)))))
  31               ,@body))
  32        (sane-lowlevel::sane_exit))))