cd into ISOs files folder
cd path/to/isos/folder
loop all ISO files and convert them to mkv
# use all ISO childs
for x in $(find . -name '*.ISO'); do
# make dir of /output/path/ISO_FILE.ISO/*.mkv
mkdir -p "/output/path//${x#'./'}";
# convert them all
/Applications/MakeMKV.app/Contents/MacOS/makemkvcon mkv iso:$x all "/output/path/${x#'./'}";
done;