Simple script to create macOS application bundles

appgen

#!/usr/bin/env bash

if [[ $1 == "--help" ]] || [[ $1 == "-h" ]]; then
  echo "Usage: appgen [--help]"
  echo ""
  echo "AppGen is a tool for creating macOS Application bundles from the terminal. This is an interactive script and doesn't require any arguments to be passed."
  echo ""
  echo "+ Application Name: Name of the application. Cannot contain special characters, such as \\, \" and *"
  echo "+ Bundle Identifier: The identifier of the application. Usually in the form of \"com.website.appname\" without quotes where com.website is a reversed domain name."
  echo "+ Script To Execute: This is a shell script or binary and will be ran when you start your application."
  echo "+ Application Icon: The icon to display on the application. Has to be in ICNS format. ICNS is a special format for macOS and it can be created with Image2icon from the App Store."
  echo "+ Application Version: Version of the application, such as 1.0 or 3.1.2 ."
  echo "+ Minimum System Version: Minimum macOS version to run the application, such as 10.12.6 (latest macOS Sierra) or 10.7.2 (OS X Lion)."
  exit 0
fi
read -p "Name of the application: " appname
read -p "Bundle identifier: " appidentifier
read -p "Script to execute when ran: " targetscript
read -p "Application icon (.icns): " targeticns
read -p "Application version: " vernum
read -p "Minimum system version (10.x.x): " minosnum
echo ""
echo "Creating \"${appname}.app\"..."

mkdir "./${appname}.app"
mkdir "./${appname}.app/Contents"
mkdir "./${appname}.app/Contents/MacOS"
mkdir "./${appname}.app/Contents/Resources"

echo "Creating Info.plist..."
echo '<?xml version="1.0" encoding="UTF-8"?>' > "./${appname}.app/Contents/Info.plist"
echo '<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">' >> "./${appname}.app/Contents/Info.plist"
echo '<plist version="1.0">' >> "./${appname}.app/Contents/Info.plist"
echo '<dict>' >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundleExecutable</key>' >> "./${appname}.app/Contents/Info.plist"
echo '<string>exec</string>' >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundleIconFile</key>' >> "./${appname}.app/Contents/Info.plist"
echo '<string>Icon.icns</string>' >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundlePackageType</key>' >> "./${appname}.app/Contents/Info.plist"
echo '<string>APPL</string>' >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundleIdentifier</key>' >> "./${appname}.app/Contents/Info.plist"
echo "<string>${appidentifier}</string>" >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundleName</key>' >> "./${appname}.app/Contents/Info.plist"
echo "<string>${appname}</string>" >> "./${appname}.app/Contents/Info.plist"
echo '<key>CFBundleShortVersionString</key>' >> "./${appname}.app/Contents/Info.plist"
echo "<string>${vernum}</string>" >> "./${appname}.app/Contents/Info.plist"
echo '<key>LSMinimumSystemVersion</key>' >> "./${appname}.app/Contents/Info.plist"
echo "<string>${minosnum}</string>" >> "./${appname}.app/Contents/Info.plist"
echo '</dict>' >> "./${appname}.app/Contents/Info.plist"
echo '</plist>' >> "./${appname}.app/Contents/Info.plist"

echo '#!/usr/bin/env bash' > "./${appname}.app/Contents/MacOS/exec"
echo '' >> "./${appname}.app/Contents/MacOS/exec"
echo '# This script is used to launch your script. Do' >> "./${appname}.app/Contents/MacOS/exec"
echo '# not modify this script unless you know what' >> "./${appname}.app/Contents/MacOS/exec"
echo '# you are doing.' >> "./${appname}.app/Contents/MacOS/exec"
echo '' >> "./${appname}.app/Contents/MacOS/exec"
echo "# Make the working directory the script's folder" >> "./${appname}.app/Contents/MacOS/exec"
echo 'cd "${0%/*}"' >> "./${appname}.app/Contents/MacOS/exec"
echo '' >> "./${appname}.app/Contents/MacOS/exec"
echo '# Run main_script in a new Terminal window' >> "./${appname}.app/Contents/MacOS/exec"
echo 'open ./main_script' >> "./${appname}.app/Contents/MacOS/exec"

echo "Copying the script inside the application..."
cp "${targetscript}" "./${appname}.app/Contents/MacOS/main_script"
chmod +x "./${appname}.app/Contents/MacOS/main_script"
chmod +x "./${appname}.app/Contents/MacOS/exec"

echo "Copying the icon inside the application..."
cp "${targeticns}" "./${appname}.app/Contents/Resources/Icon.icns"

echo "Done."