How to get the wi-fi connection status from terminal?

Sometimes, when waking up my mac, I get the message "Alert: No internet connection" on the Wi-Fi icon. I can solve it everytime by turning Wi-Fi off and on again. Is there a terminal command I can use to detect the current connection status? I would like to run a script to turn Wi-Fi off and on automatically on waking up if so. Other solutions are welcome, too.