How to manually create icns files using iconutil?

Question

When I\'m validating my app I get this error:

the application bundle does not contain an icon in ICNS format, containing both a 512x512

Answer 1

Here's a function mostly based off Henry's example (could be useful in ~/.bash_profile):

mkicns() {
    if [[ -z "$*" ]] || [[ "${*##*.}" != "png" ]]; then
        echo "Input file invalid"
    else
        filename="${1%.*}"
        mkdir "$filename".iconset
        for i in 16 32 128 256 ; do
            n=$(( i * 2 ))
            sips -z $i $i "$1" --out "$filename".iconset/icon_${i}x${i}.png
            sips -z $n $n "$1" --out "$filename".iconset/icon_${i}x${i}@2x.png
            [[ $n -eq 512 ]] && \
            sips -z $n $n "$1" --out "$filename".iconset/icon_${n}x${n}.png
            (( i++ ))
        done
        cp "$1" "$filename".iconset/icon_512x512@2x.png
        iconutil -c icns "$filename".iconset
        rm -r "$filename".iconset
    fi
}

Usage:

$ mkicns "filename.png"  # double-quote if spaces exist in filename

Creates 10 sizes from 16x16 to 512x512@2x; accepts input images in .png format only.