Install Flutter

install-flutter.sh

if [ $(which flutter) ]; then
    echo "flutter already installed"
else
    flutter_dir=/opt/flutter
    sudo mkdir $flutter_dir
    sudo chown $(whoami) $flutter_dir                                       # because users should be able to update
    sudo chmod -R 0750 $flutter_dir                                         # because users should be able to update
    git clone -b stable https://github.com/flutter/flutter.git $flutter_dir # get latest stable flutter
    sudo ln -s /opt/flutter/bin/flutter /usr/bin/flutter                    # put on path
    flutter --version                                                       # start once to initialize it
    flutter doctor
fi