查看 elasticsearch版本号

输入命令：

curl -XGET localhost:9200

得到：

{
  "name" : "OmUcqLr",
  "cluster_name" : "elasticsearch",
  "cluster_uuid" : "AQHIcDW_Q9K80UpISSdJ6A",
  "version" : {
    "number" : "5.6.16", #版本号
    "build_hash" : "3a740d1",
    "build_date" : "2019-03-13T15:33:36.565Z",
    "build_snapshot" : false,
    "lucene_version" : "6.6.1"
  },
  "tagline" : "You Know, for Search"
}