如何使用jq从JSON获取密钥名称

Question

curl http://testhost.test.com:8080/application/app/version | jq '.version' | jq '.[]'

上面的命令只输出如下值:

"madireddy@test.com"

"2323"

"test"

"02-03-2014-13:41"

"application"

如何获得密钥名称,如下所示:

email

versionID

context

date

versionName

Answer 1

您可以使用:

$ jq 'keys' file.json

$ cat file.json:
{ "Archiver-Version" : "Plexus Archiver", "Build-Id" : "", "Build-Jdk" : "1.7.0_07", "Build-Number" : "", "Build-Tag" : "", "Built-By" : "cporter", "Created-By" : "Apache Maven", "Implementation-Title" : "northstar", "Implementation-Vendor-Id" : "com.test.testPack", "Implementation-Version" : "testBox", "Manifest-Version" : "1.0", "appname" : "testApp", "build-date" : "02-03-2014-13:41", "version" : "testBox" }

$ jq 'keys' file.json
[
  "Archiver-Version",
  "Build-Id",
  "Build-Jdk",
  "Build-Number",
  "Build-Tag",
  "Built-By",
  "Created-By",
  "Implementation-Title",
  "Implementation-Vendor-Id",
  "Implementation-Version",
  "Manifest-Version",
  "appname",
  "build-date",
  "version"
]

更新:使用这些键创建BASH数组:

使用BASH 4+:

mapfile -t arr < <(jq -r 'keys[]' ms.json)

在较旧的BASH上,您可以:

arr=()
while IFS='' read -r line; do
   arr+=("$line")
done < <(jq 'keys[]' ms.json)

然后打印出来:

printf "%s\n" ${arr[@]}

"Archiver-Version"
"Build-Id"
"Build-Jdk"
"Build-Number"
"Build-Tag"
"Built-By"
"Created-By"
"Implementation-Title"
"Implementation-Vendor-Id"
"Implementation-Version"
"Manifest-Version"
"appname"
"build-date"
"version"

Answer 2

要获取 JSON 中更深节点上的键：

echo '{"data": "1", "user": { "name": 2, "phone": 3 } }' | jq '.user | keys[]'
"name"
"phone"

Answer 3

你需要使用jq 'keys[]'.例如:

echo '{"example1" : 1, "example2" : 2, "example3" : 3}' | jq 'keys[]'

将输出一行分隔列表:

"example1"
"example2"
"example3"

Answer 4

如果您的输入是对象数组，

[
  { 
    "a01" : { "name" : "A", "user" : "B" }
  },
  { 
    "a02" : { "name" : "C", "user" : "D" }
  }
]

尝试：

jq '.[] | keys[]'

Answer 5

奇怪的是，接受的答案实际上并没有准确回答 Q，因此作为参考，这里有一个解决方案：

\n

$ jq -r 'keys_unsorted[]' file.json\n

\n

Answer 6

要将密钥在一行上打印为 csv：

echo '{"b":"2","a":"1"}' | jq -r 'keys | [ .[] | tostring ] | @csv'

输出：

"a","b"

为了 csv 完整性......在一行上打印值作为 csv：

echo '{"b":"2","a":"1"}' | jq -rS . | jq -r '. | [ .[] | tostring ] | @csv'

输出：

"1","2"

Answer 7

echo '{"ab": 1, "cd": 2}' | jq -r 'keys[]' 每行打印所有键一个键，不带引号。

ab
cd

Answer 8

结合以上答案，您想向jq请求原始输出，因此最后一个过滤器应为：

     cat input.json | jq -r 'keys'

从jq帮助：

     -r     output raw strings, not JSON texts;