concat.sh

#!/bin/bash

for f in "$1"/*; do 
    echo "file '$f'" >> "$1".list
done

ffmpeg -f concat -safe 0 -i "$1".list -c copy "$1".mkv

rm "$1".list

echo -ne "Delete folder $1? (y/N) "
read -r delete

case $delete in
    "y" | "Y" )
        rm -r "$1"
    ;;
esac