使用 CLI 查看服务帮助

• 可以键入 help 来查看适用于服务的所有命令：

  caji:configuration services nis> help
  Subcommands that are valid in this context:
  
     help [topic]         => Get context-sensitive help. If [topic] is specified,
                             it must be one of "builtins", "commands", "general",
                             "help", "script" or "properties".
  
     show                 => Show information pertinent to the current context
  
     commit               => Commit current state, including any changes
  
     done                 => Finish operating on "nis"
  
     enable               => Enable the nis service
  
     disable              => Disable the nis service
  
     get [prop]           => Get value for property [prop]. ("help properties"
                             for valid properties.) If [prop] is not specified,
                             returns values for all properties.
  
     set [prop]           => Set property [prop] to [value]. ("help properties"
                             for valid properties.) For properties taking list
                             values, [value] should be a comma-separated list of
                             values.