Script to convert png icon to macOS icns

makeicns.sh

#!/bin/bash
# Usage: ./makeicns.sh iconimage.png
#

INPUT="$1"
SOURCE_IMAGE="${INPUT:r}"

mkdir -p "$SOURCE_IMAGE.iconset"

# Resize operations
sips -z 16 16     "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_16x16.png"
sips -z 32 32     "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_16x16@2x.png"
sips -z 32 32     "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_32x32.png"
sips -z 64 64     "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_32x32@2x.png"
sips -z 128 128   "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_128x128.png"
sips -z 256 256   "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_128x128@2x.png"
sips -z 256 256   "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_256x256.png"
sips -z 512 512   "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_256x256@2x.png"
sips -z 512 512   "$INPUT" --out "$SOURCE_IMAGE.iconset/icon_512x512.png" # Fixed filename here
cp "$INPUT" "$SOURCE_IMAGE.iconset/icon_512x512@2x.png"

# Convert folder to .icns file
iconutil -c icns "$SOURCE_IMAGE.iconset" -o "$SOURCE_IMAGE.icns"

# Clean up the temporary iconset folder
rm -rf "$SOURCE_IMAGE.iconset"