title: redis-cli: using "-r -1" exits immediately instead of running command indefinitely
body: <p>I'm trying to monitor the behavior/uptime of a Redis cluster (on AWS ElastiCache) while performing various maintenance operations on it. According to <a href="https://redis.io/topics/rediscli" rel="nofollow noreferrer">this doc</a> (under "Continuously Run Same Command"), I should be able to use the "-r" flag with the argument "-1" to run a command continuously. However, when I run my PING command with this option, it terminates immediately with no output but the status code indicates success:</p>
  
  <pre><code>$ root@00460dccc7d9:/data# redis-cli -h my-host.txz1ua.ng.0001.use1.cache.amazonaws.com -r -1 -i 1 PING
  $ root@00460dccc7d9:/data# echo $?
  0
  </code></pre>
  
  <p>If I use other numbers, it works as expected:</p>
  
  <pre><code>root@00460dccc7d9:/data# redis-cli -h my-host.txz1ua.ng.0001.use1.cache.amazonaws.com -r 3 -i 1 PING
  PONG
  PONG
  PONG
  root@00460dccc7d9:/data#
  </code></pre>
  
  <p>Anyone know what might be going on?</p>