title: Redis command to get all available channels for pub/sub?
body: <p>I search through redis command list. I couldn't find the command to get all the available channels in redis pub/sub. In meteor server, the equivalent command is <code>LISTCHANNELS</code>, where it lists all known channels, the number of messages stored on each one and the number of current subscribers.</p>
  
  <p>I have a cron that needs to periodically know about the available channels. Does redis have native command for this? Or I need to find a way to implement it myself?</p>