多PHP版本使用 composer

/usr/loca/php5.6/bin/php  => link to : /usr/bion/php56
/usr/local/php7.4/bin/php  => link to : /usr/bin/php74


// 案例
mkdir laravel8
cd laravel8
wget https://getcomposer.org/download/2.1.8/composer.phar

php74 composer.phar global require laravel/installer