For feedback it depends on the device. Cheap light switches, for example, might just have on and off commands. Better versions will have a status command as w

For feedback it depends on the device. Cheap light switches, for example, might just have on and off commands. Better versions will have a status command as well, and maybe a multi-level dim, etc. In my case the sprinkler switch did have status capability, but my cheesy little shell script was just assuming the commands succeeded.