使用jq在单行上提取特定属性值和输出

Question

我有这个ElasticSearch快照输出,并想将其降低到打印,在一行上,从各snapshot的的值 end_time_in_millis,并snapshot用空格分开的属性:

1429609790767 snapshot_1
1429681169896 snapshot_2

基本上是输出

• cat data | jq '.snapshots[].end_time_in_millis' 和
• cat data | jq '.snapshots[].snapshot'

但在一条线上合并.

我在看,map但无法弄清楚如何应用它; 也读这个答案我尝试:

cat data  | jq '.snapshots[] | map(. |= with_entries( select( .key == ( "snapshot") ) ) )'

但这会产生大量错误和null输出.

数据:

{
  "snapshots": [
    {
      "shards": {
        "successful": 1,
        "failed": 0,
        "total": 1
      },
      "failures": [],
      "snapshot": "snapshot_1",
      "indices": [
        "myindex1"
      ],
      "state": "SUCCESS",
      "start_time": "2015-04-21T09:45:47.041Z",
      "start_time_in_millis": 1429609547041,
      "end_time": "2015-04-21T09:49:50.767Z",
      "end_time_in_millis": 1429609790767,
      "duration_in_millis": 243726
    },
    {
      "shards": {
        "successful": 1,
        "failed": 0,
        "total": 1
      },
      "failures": [],
      "snapshot": "snapshot_2",
      "indices": [
        "myindex1"
      ],
      "state": "SUCCESS",
      "start_time": "2015-04-22T05:36:02.333Z",
      "start_time_in_millis": 1429680962333,
      "end_time": "2015-04-22T05:39:29.896Z",
      "end_time_in_millis": 1429681169896,
      "duration_in_millis": 207563
    }
  ]
}

Answer 1

使用此过滤器:

.snapshots[] | "\(.end_time_in_millis) \(.snapshot)"

这会为每个快照构建一个字符串,其中包含结束时间和快照名称.

只需确保使用该-r选项即可获得原始输出.