json - 如何使用 gcloud 命令从 json 中仅提取名称字段？

Question

我是 gcp 和 linux 的新手。我正在尝试从 json 获取名称使用gcloud格式命令。以下是命令和输出:

gcloud firestore indexes composite list --format=json

输出:

[
  {
    "fields": [
      {
        "fieldPath": "is_active",
        "order": "ASCENDING"
      },
      {
        "fieldPath": "created_at",
        "order": "DESCENDING"
      },
      {
        "fieldPath": "__name__",
        "order": "ASCENDING"
      }
    ],
    "name": "projects/emc-ema-simcs-d-286404/databases/(default)/collectionGroups/customer/indexes/CICAgNjbhowK",
    "queryScope": "COLLECTION",
    "state": "READY"
  }

如何获得name使用 gcloud 命令的值。我尝试使用:gcloud firestore indexes composite list | grep name | awk -F'name: ' '{print $2}'但这没有给出任何输出。

请帮忙!

谢谢普里蒂什

Answer 1

假设您的工具输出确实没有无与伦比的 [在开始时，这会使其无效 JSON，如您在问题中提供的示例所示，而是同时具有 [和]或者两者都没有，即它是有效的 JSON。

如果输出以 [ 开头并以 ] 结尾那么你会使用jq如:

gcloud firestore indexes composite list --format=json | jq -r '.[0] .name'

否则你会使用 jq如:

gcloud firestore indexes composite list --format=json | jq -r '.name'

例如，使用 cat file<N>代替gcloud firestore indexes composite list --format=json我没有:

$ cat file1
[
  {
    "fields": [
      {
        "fieldPath": "is_active",
        "order": "ASCENDING"
      },
      {
        "fieldPath": "created_at",
        "order": "DESCENDING"
      },
      {
        "fieldPath": "__name__",
        "order": "ASCENDING"
      }
    ],
    "name": "projects/emc-ema-simcs-d-286404/databases/(default)/collectionGroups/customer/indexes/CICAgNjbhowK",
    "queryScope": "COLLECTION",
    "state": "READY"
  }
]
$
$ cat file1 | jq -r '.[0] .name'
projects/emc-ema-simcs-d-286404/databases/(default)/collectionGroups/customer/indexes/CICAgNjbhowK

$ cat file2
  {
    "fields": [
      {
        "fieldPath": "is_active",
        "order": "ASCENDING"
      },
      {
        "fieldPath": "created_at",
        "order": "DESCENDING"
      },
      {
        "fieldPath": "__name__",
        "order": "ASCENDING"
      }
    ],
    "name": "projects/emc-ema-simcs-d-286404/databases/(default)/collectionGroups/customer/indexes/CICAgNjbhowK",
    "queryScope": "COLLECTION",
    "state": "READY"
  }
$
$ cat file2 | jq -r '.name'
projects/emc-ema-simcs-d-286404/databases/(default)/collectionGroups/customer/indexes/CICAgNjbhowK