#!/bin/bash
 
ordner="bilder/"
bilder=(`ls $ordner | sort -n`)
 
max=`ls $ordner | wc -l`
max=$(( $max - 1 ))
 
y=0
while [ $y -le $max ]
do
        newmax=$(( $y + 2 ))
        while [ $y -le $newmax ]
        do
         echo ${bilder[$y]}
         y=$(( $y + 1 ))
        done
        echo "Aktion"
        y=$(( $newmax + 1 ))
done