Using feh to sort images

In the beginning of the year I wrote a tool to label images but I don't use it anymore. Nowadays I use feh for this.

Feh has customizable actions that are by default mapped to the keys 1 to 9. For example this command:

feh -ZFd --action1 "rm '%f'" * --action2 "cp '%f' label-x"

The key 1 deletes the current file and the key 2 copies the current file to the folder label-x. When the command is run feh moves to the next image which is perfect for fast processing of images. The options ZFd are: auto-zoom, fullscreen and show filename in the left-top corner.