export ROS_HOSTNAME, ROS_MASTER_URI configuration problem

edit

Hello all,

I was trying all day to figure out why my cmd won't accept my arrow keys as input for the turtlesim example. At first I though there was some configuration problem with the shell I use (zsh). After experimenting a little I noticed that I need to export ROS_HOSTNAME and ROS_MASTER_URI in all 3 tabs I need to run the turtlsime example. So in each tab I go like:

1. export ROS_HOSTNAME=localhost --- export ROS_MASTER_URI=http://localhost:11311 --- roscore
2. export ROS_HOSTNAME=localhost --- export ROS_MASTER_URI=http://localhost:11311 --- rosrun turtlesim turtlesim_node
3. export ROS_HOSTNAME=localhost --- export ROS_MASTER_URI=http://localhost:11311 --- rosrun turtlesim turtle_teleop_key

Only then my cmd will accept my arrow keys as input and I will see the turtle moving. Any idea what I am doing wrong? Is there a way I can avoid this? Like run it once, even if I need to restart my PC?

Thank you