Retrieves the list of selected/active channels as an array of channel names.
Some commands require channel names as arguments, and using this command to get the selected channels always ensures that the channels you have selected get operated on, rather than having to hard code the channel names.
// Set and get active Channels
// First select some channels
selectProperty TranslationY -a;
selectProperty TranslationZ -a;
// Print out the channel names we just selected
$channels = `getChannels`;