feh -r /user/obrazky <===> prohlidne celou slozku i podslozku v adresari user/obrazky
feh -L '%w %h %f' | awk '{ if ($1 > $2) { print $0 } }' | cut -d ' ' -f 3- | feh -f - <===> Show landscape pictures (image width greater than height) in the current directory.
feh -irFarial/14 -O index.jpg ~/Pictures <===> Make an index print of ~/Pictures and all directories below it, using 14 point Arial to write the image info under each thumbnail. Save the image as index.jpg and don't display it, just exit. Note that this even works without a running X server
feh --action 'rm %F' -rl --max-dimension 1000x800 <===> Recursively remove all images with dimensions below or equal to 1000x800 pixels from the current directory.
