Command_line HTTP request not firing

I am trying to use the command_line switch to fire HTTP requests. While I have successfully configured my Energenie switches to turn on and off using this method, I am having trouble getting it to fire requests to my Squeezebox (LMS) server.
Here is the relevant extract from my configuration.yaml:

switch:
  - platform: command_line
    switches:
      lounge_skip_next:
        command_on: '/usr/bin/curl -X GET http://192.168.1.251:9000/status.html?player=cc:cc:dd:1f:aa:15&p0=playlist&p1=jump&p2=%2b1'

When I turn this switch on from the HA console nothing seems to be executed, and nothing is written to the HA log. I’m running HA 0.61.1 on Lubuntu.
Any idea why my HTTP request isn’t firing?

Just answered my own question - I guess there were characters in the HTTP request that needed to be escaped, so enclosing the request in double-quotes did the trick