jq cheatsheet

安装

brew install jq # macOS
apt-get install jq # Debian/Ubuntu
zypper in jq # OpenSUSE
dnf install jq
pacman -S jq
chocolatey install jq

取值

echo '{
  "string": "Hello, world!",
  "number": 233,
  "object": {
    "key": "value"  
  },
  "string-array": ["Ubuntu", "Deepin", "OpenSUSE", "CentOS"],
  "object-array": [{
    "key": "value"
  }]
}' > tmp.json

cat tmp.json | jq .string #> "Hello, world!"
cat tmp.json | jq .string -r #> Hello, world!
cat tmp.json | jq .number #> 233
cat tmp.json | jq .object 
{
  "key": "value"
}

cat tmp.json | jq '."string-array"'
[
  "Ubuntu",
  "Deepin",
  "OpenSUSE",
  "CentOS"
]

cat tmp.json | jq '."string-array"[0]' #> "Ubuntu"

cat tmp.json | jq '."object-array"[0]'
{
  "key": "value"
}

cat tmp.json | jq '."object-array"[0].key' #> "value"

cat tmp.json | jq '. | keys'
[
  "number",
  "object",
  "object-array",
  "string",
  "string-array"
]

cat tmp.json | jq '. | keys | length' #> 5

echo '{
  "string": "Hello, world!",
  "number": 233,
  "object": {
    "key": "value"  
  },
  "string-array": ["Ubuntu", "Deepin", "OpenSUSE", "CentOS"],
  "object-array": [{
    "key": "value"
  }]
}' > tmp.json

cat tmp.json | jq .string #> "Hello, world!"
cat tmp.json | jq .string -r #> Hello, world!
cat tmp.json | jq .number #> 233
cat tmp.json | jq .object 
{
  "key": "value"
}

cat tmp.json | jq '."string-array"'
[
  "Ubuntu",
  "Deepin",
  "OpenSUSE",
  "CentOS"
]

cat tmp.json | jq '."string-array"[0]' #> "Ubuntu"

cat tmp.json | jq '."object-array"[0]'
{
  "key": "value"
}

cat tmp.json | jq '."object-array"[0].key' #> "value"

cat tmp.json | jq '. | keys'
[
  "number",
  "object",
  "object-array",
  "string",
  "string-array"
]

cat tmp.json | jq '. | keys | length' #> 5

获取 JSON 对象的所有键值

echo '{
  "id": "001",
  "name": "Apple",
  "size": "large",
  "vendor": "N/A"
}' | jq -r ' keys[]'

获取指定数组元素

** JSON Array: 根据 name 获得对应 id 的值

echo '[
  { "id": "001", "name": "Apple" },
  { "id": "002", "name": "Banana" }
]' | jq -r '.[] | select(.name == "Apple") | .id'

** JSON Object: 根据 name 获得对应 id 的值

echo '{
  "001": { "name": "Apple" },
  "002": { "name": "Banana" }
}' | jq -r 'keys[] as $k | select(.[$k].name == "Apple") | "\($k)" '

修改

修改字符串

echo '{
  "value": "hello"
}' > tmp.json

替换字符串

jq '.value = "hey"' tmp.json

拼接字符串

jq '.value += ", world"' tmp.json

修改 JSON Object

echo '{
  "value": "hello"
}' > tmp.json

添加字段

jq '.version = "v1"' tmp.json

删除字段

jq 'del(.value)' tmp.json

N/A

修改 JSON Array

参数化

echo '{}' | jq --arg NAME "Apple" --arg COLOR "Red" ' .name = $NAME | .color = $COLOR '

参考文献

jq GitHub Page