-(defvar binhex-decoder-switches '("-d")
- "*List of command line flags passed to the command named by binhex-decoder-program.")
+(defcustom binhex-decoder-switches '("-d")
+ "*List of command line flags passed to the command `binhex-decoder-program'."
+ :group 'gnus-extract
+ :type '(repeat string))
+
+(defcustom binhex-use-external
+ (executable-find binhex-decoder-program)
+ "*Use external binhex program."
+ :group 'gnus-extract
+ :type 'boolean)