robert@wolf:~$ gphoto2 --usage
Usage: gphoto2 [-?|--help] [--usage] [--debug] [--quiet] [--force-overwrite]
        [-v|--version] [--list-cameras] [--list-ports] [--stdout]
        [--stdout-size] [--auto-detect] [--port=path] [--speed=speed]
        [--camera=model] [--filename=filename] [--usbid=usbid]
        [-a|--abilities] [-f|--folder folder] [-R|--recurse] [--no-recurse]
        [-l|--list-folders] [-L|--list-files] [-m|--mkdir STRING]
        [-r|--rmdir STRING] [-n|--num-files] [-p|--get-file STRING]
        [-P|--get-all-files] [-t|--get-thumbnail STRING]
        [-T|--get-all-thumbnails] [--get-raw-data=STRING] [--get-all-raw-data]
        [--get-audio-data=STRING] [--get-all-audio-data]
        [-d|--delete-file STRING] [-D|--delete-all-files]
        [-u|--upload-file STRING] [--config] [--capture-preview]
        [--capture-image] [--capture-movie] [--capture-sound]
        [--show-exif=STRING] [--show-info=STRING] [--summary] [--manual]
        [--about] [--shell]