can`t run "sudo ./kinect2_bridge",Neither run roscore on master or local is work,help

[Nicersmeng]

test@ptiplex-103:~/workspace/ros/catkin/devel/lib/kinect2_bridge$ sudo ./kinect2_bridge
[sudo] password for test:
[FATAL] [1515638372.412132523]: ROS_MASTER_URI is not defined in the environment. Either type the following or (preferrably) add this to your ~/.bashrc file in order set up your local machine as a ROS master:

export ROS_MASTER_URI=http://localhost:11311

then, type 'roscore' in another shell to actually launch the master program.