获取到给定元素的完整路径

Question

我已经从 Firefox 中导出了书签，在我的例子中是安静的大型 JSON。我对带有 guid _0no-4e9woLW 的 JSON 对象感兴趣，例如这个：

{
  "foo": {
    "bar": {
      "zoo": {
        "guid": "_0no-4e9woLW",
        "title": "frontend",
        "index": 3,
        "dateAdded": 1614198626454000,
        "lastModified": 1619505016472000,
        "id": 16518,
        "typeCode": 2,
        "type": "text/x-moz-place-container",
        "children": [
          {
            "guid": "2L7ZsYTM2RX0",
            "title": "css child override parent style",
            "index": 0,
            "dateAdded": 1614198648005000,
            "lastModified": 1614198648005000,
            "id": 16519,
            "typeCode": 1,
            "type": "text/x-moz-place",
            "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+override+parent+style"
          },
          {
            "guid": "x3JHTAezzyI8",
            "title": "css child parent inheritance",
            "index": 1,
            "dateAdded": 1614198648096000,
            "lastModified": 1614198648096000,
            "id": 16520,
            "typeCode": 1,
            "type": "text/x-moz-place",
            "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+parent+inheritance"
          }
        ]
      }
    }
  }
}

是否有可能以某种方式获得到"guid": "_0no-4e9woLW" 的完整路径？ guid 键在 JSON 中是唯一的。我的目标是输入类似jq '["full path I've somehow previously obtained"]["children"].title'

我会得到：

css child override parent style
css child parent inheritance

我当然可以手动执行此操作，但我太懒了。

Answer 1

如果没有 JSON 的全部知识，当使用 path 系列函数（即 getpath/1）时，这样的事情应该可以工作

( paths | select(.[-1] == "guid") ) as $p | 
  if getpath($p)  == "_0no-4e9woLW" then getpath($p[:-1] + ["children"])[].title else empty end

上面的构造意味着，选择所有包含名为guid 的叶键的路径并将它们存储在一个变量中，并仅过滤其值为"_0no-4e9woLW" 的路径。在选定的路径上，修剪子节点（$p[:-1] 删除"guid"）并添加节点"children" 并获取构造的新路径的值（使用getpath/1）。从 JSON 值中提取 .title 字段

^{jqplay demo}

Answer 2

使用recurse 可以轻松到达对象：

jq -r 'recurse |
       select(type=="object" and .guid == "_0no-4e9woLW")
       .children[].title' firefox.json

Answer 3

• 通过 guid 访问节点：

  .. | objects | select( .guid == … )
  

  因此，您将使用以下内容来获取 _0no-4e9woLW 的孩子的标题：

  .. | objects | select( .guid == "_0no-4e9woLW" ) | .children[].title
  

  Demo on jqplay

• 保存路径：

  path( … )               # As JSON
  

  path( … ) | join(".")   # As dotted path
  

  将… 替换为返回您想要其路径的节点的表达式。

  例如，

  path( .. | objects | select( .guid == "_0no-4e9woLW" ) )   # [ "foo", "bar", "zoo" ]
  

  Demo on jqplay

  path( .. | objects | select( .guid == "_0no-4e9woLW" ) ) | join(".")   # "foo.bar.zoo"
  

  Demo on jqplay

• 使用路径抓取对象：

  getpath( … )                                      # From JSON
  

  getpath( … | split(".") | map(tonumber? // .) )   # From dotted path
  

  将… 替换为返回先前保存路径的表达式。

  例如，

  getpath( [ "foo", "bar", "zoo" ] ).children[].title
  

  Demo on jqplay

  getpath( "foo.bar.zoo" | split(".") | map(tonumber? // .) ).children[].title
  

  Demo on jqplay

Answer 4

json2jqpath.jq file.json 
.
.foo
.foo|.bar
.foo|.bar|.zoo
.foo|.bar|.zoo|.children
.foo|.bar|.zoo|.children|.[]
.foo|.bar|.zoo|.children|.[]|.dateAdded
.foo|.bar|.zoo|.children|.[]|.guid
.foo|.bar|.zoo|.children|.[]|.id
.foo|.bar|.zoo|.children|.[]|.index
.foo|.bar|.zoo|.children|.[]|.lastModified
.foo|.bar|.zoo|.children|.[]|.title
.foo|.bar|.zoo|.children|.[]|.type
.foo|.bar|.zoo|.children|.[]|.typeCode
.foo|.bar|.zoo|.children|.[]|.uri
.foo|.bar|.zoo|.dateAdded
.foo|.bar|.zoo|.guid
.foo|.bar|.zoo|.id
.foo|.bar|.zoo|.index
.foo|.bar|.zoo|.lastModified
.foo|.bar|.zoo|.title
.foo|.bar|.zoo|.type
.foo|.bar|.zoo|.typeCode

显示guid 在多个唯一路径中显示为叶子。 如果只有一个你就完蛋了 （假设您知道该值存在） 使用多个路径，您需要检查该值是否存在 它是您感兴趣的对象。

json2jqpath.jq file.json | grep guid
.foo|.bar|.zoo|.children|.[]|.guid
.foo|.bar|.zoo|.guid

将给定值附加到路径会返回包含它们的对象

jq '.foo|.bar|.zoo|.children|.[]|.guid="_0no-4e9woLW"' file.json 
{
  "guid": "_0no-4e9woLW",
  "title": "css child override parent style",
  "index": 0,
  "dateAdded": 1614198648005000,
  "lastModified": 1614198648005000,
  "id": 16519,
  "typeCode": 1,
  "type": "text/x-moz-place",
  "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+override+parent+style"
}
{
  "guid": "_0no-4e9woLW",
  "title": "css child parent inheritance",
  "index": 1,
  "dateAdded": 1614198648096000,
  "lastModified": 1614198648096000,
  "id": 16520,
  "typeCode": 1,
  "type": "text/x-moz-place",
  "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+parent+inheritance"
}


jq '.foo|.bar|.zoo|.guid="_0no-4e9woLW"' file.json 
{
  "guid": "_0no-4e9woLW",
  "title": "frontend",
  "index": 3,
  "dateAdded": 1614198626454000,
  "lastModified": 1619505016472000,
  "id": 16518,
  "typeCode": 2,
  "type": "text/x-moz-place-container",
  "children": [
    {
      "guid": "2L7ZsYTM2RX0",
      "title": "css child override parent style",
      "index": 0,
      "dateAdded": 1614198648005000,
      "lastModified": 1614198648005000,
      "id": 16519,
      "typeCode": 1,
      "type": "text/x-moz-place",
      "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+override+parent+style"
    },
    {
      "guid": "x3JHTAezzyI8",
      "title": "css child parent inheritance",
      "index": 1,
      "dateAdded": 1614198648096000,
      "lastModified": 1614198648096000,
      "id": 16520,
      "typeCode": 1,
      "type": "text/x-moz-place",
      "uri": "https://www.google.com/search?client=firefox-b-d&q=css+child+parent+inheritance"
    }
  ]
}

json2jqpath.jq