Laravel v4.2のartisanコマンドでportを指定する．

# Laravel v4.2の'artisan serve'では，デフォルトで8000番ポートが使われる．

$ php artisan serve
> Laravel development server started on http://localhost:8000

# 別のターミナルから実行．
$ php artisan serve
# error
> [Sun Jul 26 21:30:38 2015] Failed to listen on localhost:8000 (reason: Address already in use)

# portを指定して実行する．
$ php arisan serve --port=9000
> Laravel development server started on http://localhost:9000