ruby on railsのチュートリアルをクラウド９で勉強中ですが、rails s -p /PORT -b /IPでサーバーを起動しようとするとエラーが出てしまいます。解決方法を教えてください。
ruby on rails チュートリアル
ruby on rails tutorial（http://railstutorial.jp/chapters/beginning?version=4.2#cha-beginning）をクラウド９で勉強し始めましたが、rails s -p /PORT -b /IPでサーバーを起動させようとすると、
/usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/server.rb:12:in `parse!': invalid argument: -p /PORT (OptionParser::InvalidArgument)
from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:315:in `parse_options'
from /usr/local/rvm/gems/ruby-2.2.1/gems/rack-1.6.4/lib/rack/server.rb:190:in `options'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/server.rb:71:in `set_environment'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/server.rb:55:in `initialize'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `new'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:75:in `server'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
from /usr/local/rvm/gems/ruby-2.2.1/gems/railties-4.2.4/lib/rails/commands.rb:17:in `<top (required)>'
from /home/ubuntu/workspace/hello_app/bin/rails:8:in `require'
from /home/ubuntu/workspace/hello_app/bin/rails:8:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/client/rails.rb:28:in `load'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/client/rails.rb:28:in `call'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/client/command.rb:7:in `call'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/client.rb:28:in `run'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/bin/spring:49:in `<top (required)>'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/binstub.rb:11:in `load'
from /usr/local/rvm/gems/ruby-2.2.1/gems/spring-1.4.0/lib/spring/binstub.rb:11:in `<top (required)>'
from /home/ubuntu/workspace/hello_app/bin/spring:13:in `require'
from /home/ubuntu/workspace/hello_app/bin/spring:13:in `<top (required)>'
from bin/rails:3:in `load'
from bin/rails:3:in `<main>'
このようなエラーがでてしまうのですが、どなたか解決方法を教えていただけないでしょうか？
プログラミング超初心者で、自分では解決できそうにありません。
よろしくお願いします。
お礼
単純に記号を読み間違えていました。 winでわかりにくい￥を＄と勘違いして読んでいました。 とても丁寧に説明頂きありがとうございます。 また、勉強頑張ります！ ほんと助かりました。