rails server 起動するとエラーが出ます。理由がわかりません。わかるかた教えてください。

Question

$ rails -b $IP -p $PORT
Error: Command '-b' not recognized
Usage: rails COMMAND [ARGS]

The most common rails commands are:
 generate    Generate new code (short-cut alias: "g")
 console     Start the Rails console (short-cut alias: "c")
 server      Start the Rails server (short-cut alias: "s")
 dbconsole   Start a console for the database specified in config/database.yml
             (short-cut alias: "db")
 new         Create a new Rails application. "rails new my_app" creates a
             new application called MyApp in "./my_app"

In addition to those, there are:
 application  Generate the Rails application code
 destroy      Undo code generated with "generate" (short-cut alias: "d")
 plugin new   Generates skeleton for developing a Rails plugin
 runner       Run a piece of code in the application environment (short-cut alias: "r")

All commands can be run with -h (or --help) for more information.


コード

Answer 1

$ rails -b $IP -p $PORT

s が抜けています。

正しくは、以下です。

$ rails s -b $IP -p $PORT