cd /Applications/MAMP/htdocs/composer config -g repo.packagist composer https://packagist.phpcomposer.comcomposer global require "laravel/installercomposer create-project laravel/laravel ldemo --prefer-dist。安装成功后，看到htdocs目录下有了新目录ldemo。需要看到vendor目录下有了autoload.php才算安装成功。如果看到有报错信息，例如
- Installing paragonie/random_compat (v9.99.99): Downloading (failed)
The "https://api.github.com/repos/paragonie/random_compat/zipball/84b4dfb120c6f9b4ff7b3685f9b8f1aa365a0c95" file could not be downloaded: failed to open stream: Operation timed out
Retrying with degraded mode, check https://getcomposer.org/doc/articles/troubleshooting.md#degraded-mode for more info
Downloading (failed)
Downloading (failed)
Downloading (failed) Failed to download paragonie/random_compat from dist: The "https://api.github.com/repos/paragonie/random_compat/zipball/84b4dfb120c6f9b4ff7b3685f9b8f1aa365a0c95" file could not be downloaded: failed to open stream: Operation timed out
Now trying to download from source那么需要重新下载random_compat.
执行 composer require paragonie/random_compat:2.*
php artisan key:generate原文：https://blog.51cto.com/3154408/2489442