Make ICNS from PNG

mkicns.sh

#!/bin/zsh
#mkicns.sh

FN=${1##*/}
DN=${1%/**}
BN=${FN%.*}

IS=iconset
ID=$BN.$IS

mkdir $ID
chdir $ID
i=\../$FN

for m r in 'n' '' '((n+1))' '@2x';do
    for n in $(seq 4 9|grep -v 6);do
        p=$((2**$m));q=$((2**$n))
        o=icon_${q}x${q}${r}\.png
        sips -z $p $p $i --out $o
    done
done

iconutil -c icns $PWD
cd $OLDPWD;rm -fr $ID