使用JQ工具实用程序解析或查看JSON数据字段，其中字段名称的键名称中带有“-”破折号

Question

我有一个JSON数据文件（如下所示），我正在尝试使用jq实用程序查找字段值。

除键名中包含-短划线字符的字段外，其他方法都可以正常工作。

如何获取（至少使用）下元素的“ field-2 ”，“ field-three 3 ”或“ field-three.url ”值？content.book1jq

我尝试了以下操作来获取值，但是对于键名中包含短划线的字段，它给了我以下错误-。我试图反斜杠-字符，但这也没有帮助。

发现错误类型：

jq: error (at <stdin>:27): null (null) and number (2) cannot be subtracted
jq: 1 compile error

jq: error: three/0 is not defined at <top-level>

jq: error: syntax error, unexpected INVALID_CHARACTER, expecting $end (Unix shell quoting issues?) at <top-level>

jq: error: syntax error, unexpected INVALID_CHARACTER, expecting FORMAT or QQSTRING_START (Unix shell quoting issues?) at <top-level>, line 1:

命令：

$ cat /tmp/my.data.json
{
  "pages": {
    "book1": [
      "page1",
      "page2-para1",
      "page3-para1-sentence1",
      "page3-para2-sentence3-word4"
    ]
  },
  "content": {
    "book1": {
      "name": "giga",
      "url": "-",
      "field1": "value1",
      "field-2": "value-2",
      "field-three": {
        "name": "THIRD",
        "url": "book1/field-three/",
        "short-url": "book1/field-three/chota-chetan"
      },
      "authur": {
        "name": "lori CHUCK",
        "displayIndex": 4
      },
      "route": "/in-gc/hindi-chini-bhai-bhai"
    }
  }
}

$ cat /tmp/my.data.json| jq ".pages"
{
  "book1": [
    "page1",
    "page2-para1",
    "page3-para1-sentence1",
    "page3-para2-sentence3-word4"
  ]
}

$ cat /tmp/my.data.json| jq ".pages.book1[0]"
"page1"

$ cat /tmp/my.data.json| jq ".pages.book1[1]"
"page2-para1"

$ cat /tmp/my.data.json| jq ".content"
{
  "book1": {
    "name": "giga",
    "url": "-",
    "field1": "value1",
    "field-2": "value-2",
    "field-three": {
      "name": "THIRD",
      "url": "book1/field-three/"
    },
    "authur": {
      "name": "lori CHUCK",
      "displayIndex": 4
    },
    "route": "/in-gc/hindi-chini-bhai-bhai"
  }
}

$ cat /tmp/my.data.json| jq ".content.book1"
{
  "name": "giga",
  "url": "-",
  "field1": "value1",
  "field-2": "value-2",
  "field-three": {
    "name": "THIRD",
    "url": "book1/field-three/"
  },
  "authur": {
    "name": "lori CHUCK",
    "displayIndex": 4
  },
  "route": "/in-gc/hindi-chini-bhai-bhai"
}

$ cat /tmp/my.data.json| jq ".content.book1.name"
"giga"

$ cat /tmp/my.data.json| jq ".content.book1.field1"
"value1"

$ cat /tmp/my.data.json| jq ".content.book1.field-2"
jq: error (at <stdin>:27): null (null) and number (2) cannot be subtracted

$ cat /tmp/my.data.json| jq ".content.book1.field-three"
jq: error: three/0 is not defined at <top-level>, line 1:
.content.book1.field-three
jq: 1 compile error

$ cat /tmp/my.data.json| jq ".content.book1.field-three.url"
jq: error: three/0 is not defined at <top-level>, line 1:
.content.book1.field-three.url
jq: 1 compile error

$ cat /tmp/my.data.json| jq ".content.book1.field\-2"       
jq: error: syntax error, unexpected INVALID_CHARACTER, expecting $end (Unix shell quoting issues?) at <top-level>, line 1:
.content.book1.field\-2                    
jq: 1 compile error

$ cat /tmp/my.data.json| jq ".content.book1.field\\-2"
jq: error: syntax error, unexpected INVALID_CHARACTER, expecting $end (Unix shell quoting issues?) at <top-level>, line 1:
.content.book1.field\-2                    
jq: 1 compile error

$ cat /tmp/my.data.json| jq ".content.book1.'field-2'"
jq: error: syntax error, unexpected INVALID_CHARACTER, expecting FORMAT or QQSTRING_START (Unix shell quoting issues?) at <top-level>, line 1:
.content.book1.'field-2'               
jq: 1 compile error

$ cat /tmp/my.data.json| jq ".content.book1.authur"
{
  "name": "lori CHUCK",
  "displayIndex": 4
}

$ cat /tmp/my.data.json| jq ".content.book1.route"
"/in-gc/hindi-chini-bhai-bhai"

$

PS： 我已经知道了，egrep所以这不是我想要的。

cat /tmp/my.data.json| jq ".content.book1"|egrep "short-url|field-2"
  "field-2": "value-2",
    "short-url": "book1/field-three/chota-chetan"

有人真的在这里做得很好：https：//jqplay.org/

Answer 1

jq中的“-”用于取反。对于带有特殊字符（例如“-”）的键名，不能使用简化的“ .keyname”语法。有几种选择，但是最可靠的选择就是使用形式.["KEY NAME"]，当链接时可以缩写为[“ KEY NAME”]，例如.a["b-c"]的简写形式.a | .["b-c"]。

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