anchor.diff:  
   (defcvar ("environ" :read-only t) (:pointer :string))
   
  -(defsyscall ("getenv" %sys-getenv) :string
  +(defsyscall (%sys-getenv "getenv") :string
     "Returns the value of an environment variable"
     (name :string))
   
  -(defsyscall ("setenv" %sys-setenv) :int
  +(defsyscall (%sys-setenv "setenv") :int
     "Changes the value of an environment variable"
     (name      :string)
     (value     :string)
     (overwrite bool-designator))
   
  -(defsyscall ("unsetenv" %sys-unsetenv) :int
  +(defsyscall (%sys-unsetenv "unsetenv") :int
     "Removes the binding of an environment variable"
     (name :string))
   
positive.code: ;;; Memory manipulation
  ;;;-------------------------------------------------------------------------
  
  (defcfun* ("memset" %sys-memset) :pointer
    (buffer :pointer)
    (value  :int)
    (length size-t))
  
negative.code:   (defconstant calendar-clock 1)
    (defconstant realtime-clock 0)
  
    (defsyscall (%sys-mach-host-self "mach_host_self") port-t)
  
    (defsyscall (%%sys-host-get-clock-service "host_get_clock_service") kern-return-t
      (host port-t)
      (id clock-id-t)
      (clock-name (:pointer clock-serv-t)))
  