I have found a command to killall simulators but does not fit my needs. I need to be able to restart a particular simulator given the udid.
I have tried shutdown and then boot the simulator using
$ xcrun simctl shutdown <udid>
$ xcrun simctl boot <udid>
$ open -a simulator
but the simulator hangs after the execution of these commands.
Xcode version: 10.3 Simulator version: iPhone XS iOS: 12.4