robert@wolf:~$ gphoto2 --help
Usage: gphoto2 [OPTION...]
  --debug                        Turn on debugging
  --quiet                        Quiet output (default=verbose)
  --force-overwrite              Overwrite files without asking.
  -v, --version                  Display version and exit
  --list-cameras                 List supported camera models
  --list-ports                   List supported port devices
  --stdout                       Send file to stdout
  --stdout-size                  Print filesize before data
  --auto-detect                  List auto-detected cameras
  --port=path                    Specify port device
  --speed=speed                  Specify serial transfer speed
  --camera=model                 Specify camera model
  --filename=filename            Specify a filename
  --usbid=usbid                  (expert only) Override USB IDs
  -a, --abilities                Display camera abilities
  -f, --folder=folder            Specify camera folder (default="/")
  -R, --recurse                  Recursion (default for download)
  --no-recurse                   No recursion (default for deletion)
  -l, --list-folders             List folders in folder
  -L, --list-files               List files in folder
  -m, --mkdir=STRING             Create a directory
  -r, --rmdir=STRING             Remove a directory
  -n, --num-files                Display number of files
  -p, --get-file=STRING          Get files given in range
  -P, --get-all-files            Get all files from folder
  -t, --get-thumbnail=STRING     Get thumbnails given in range
  -T, --get-all-thumbnails       Get all thumbnails from folder
  --get-raw-data=STRING          Get raw data given in range
  --get-all-raw-data             Get all raw data from folder
  --get-audio-data=STRING        Get audio data given in range
  --get-all-audio-data           Get all audio data from folder
  -d, --delete-file=STRING       Delete files given in range
  -D, --delete-all-files         Delete all files in folder
  -u, --upload-file=STRING       Upload a file to camera
  --config                       Configure
  --capture-preview              Capture a quick preview
  --capture-image                Capture an image
  --capture-movie                Capture a movie
  --capture-sound                Capture an audio clip
  --show-exif=STRING             Show EXIF information
  --show-info=STRING             Show info
  --summary                      Show summary
  --manual                       Show camera driver manual
  --about                        About the camera driver manual
  --shell                        gPhoto shell

Help options:
  -?, --help                     Show this help message
  --usage                        Display brief usage message