title: how to put the result of an echo command into an ansible variable
body: <p>I have $MY_VAR set to some value on the remote host, and I want to query it from a playbook
  (put it's value in an ansible variable), here's what I am seeing :</p>
  
  <pre>
     - name: put shell var into ansible var
       command: echo $MY_VAR
       register: my_var
  
     - debug: var=my_var
  </pre>
  
  <pre>
  ok: [192.168.78.10] => {
      "my_var": {
          "changed": true, 
          "cmd": [
              "echo", 
              "$my_var"
          ], 
          "delta": "0:00:00.002284", 
          "end": "2014-12-17 18:10:01.097217", 
          "invocation": {
              "module_args": "echo $my_var", 
              "module_name": "command"
          }, 
          "rc": 0, 
          "start": "2014-12-17 18:10:01.094933", 
          "stderr": "", 
          "stdout": "$my_var", 
          "stdout_lines": [
              "$my_var"
          ]
      }
  }
  
  </pre>
  
  <h2>note:</h2>
  
  <p>If I change the command to : </p>
  
  <pre><code> command: pwd
  </code></pre>
  
  <p>then I get the expected result : </p>
  
  <pre><code>"my_var": {
    "stdout": "/home/vagrant", 
    "stdout_lines": [
        "/home/vagrant"  
    ]
  }
  </code></pre>
  
  <p>It seems as if echo does not expand when called from ansible</p>