curl コマンド

curl -v -H "Accept: application/json" -H "Content-type: application/json" -X POST -d '{"user":{"first_name":"firstname","last_name":"lastname","email":"email@email.com","password":"app123","password_confirmation":"app123"}}' http://www.abc.om/

-H ヘッダー部
-X メソッド
-d データ 書き方はjson