code: function parsePlatforms() {
          var supportPlatforms = [
              { platform: 'android',          regexp: /android/ig         },
              { platform: 'ios',              regexp: /ios/ig             },
              { platform: 'firefoxos',        regexp: /firefoxos/ig       },
              { platform: 'windows8',         regexp: /windows8/ig        },
              { platform: 'browser',          regexp: /browser/ig         },
              { platform: 'amazon-fireos',    regexp: /amazon-fireos/ig   },
              { platform: 'blackberry10',     regexp: /blackberry10/ig    },
              { platform: 'windows',          regexp: /windows/ig         },
              { platform: 'wp8',              regexp: /wp8/ig             },
          ];
  
          var gruntTasks = [];
  
          supportPlatforms.forEach(function (checker) {
              if (null != _cmdline.match(checker.regexp)) {
                  gruntTasks.push('cordova_register_platform:' + checker.platform);
              }
          });
  
          return gruntTasks;
      }
docs: check command line Judge the target platforms.
  if the command line includes platform names, call grunt cordova_register_platform:<platform>.
  see '$ cordova compile --help'