Linux jq命令的使用解读

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《Linuxjq命令的使用解读》jq是一个强大的命令行工具,用于处理JSON数据,它可以用来查看、过滤、修改、格式化JSON数据,通过使用各种选项和过滤器,可以实现复杂的JSON处理任务...

一. 简介

jq 是 linux 中的命令行工具，用于处理 JSON 数据。

你可以把它看作是 JSON 的 sed 或 awk，可以用来查看、过滤、修改、格式化 JSON 数据。

Linux jq命令的使用解读

github 地址：https://github.com/stedolan/jq
jq 官方网站： https://stedolan.github.io/jq/

option	解释
-r	输出原始格式，而不是 JSON 编码 ⇒　去掉字段带的"双引号
-R	把输入当作原始字符串处理（Raw Input），而不是默认的 JSON 结构。
-c	将内容压缩到一行输出。
-s	将输入视为多个 JSON 对象，用于处理多个 JSON 对象的数组。

filter	解释
.	表示当前对象，用于访问字段或属性。
.fieldName	选择指定字段的值。
[]	用于遍历数组元素。
select(condition)	根据条件选择元素。
map(transform)	对数组中的每个元素应用转换操作。

格式转换	解释
@csv	输出 CSV 格式（数组）
@tsv	输出 Tab 分隔格式
@json	把值转成 JSON 字符串

二. 选项

2.1.

默认的格式化输出

apluser@FengYeHong-HP:~$ echo -n '{"id":1, "name":"zhangsan", "score":[75, 85, 90]}' | jq .
{
  "id": 1,
  "name": "zhangsan",
  "score": [
    75,
    85,
    90
  ]
}

2.2-c

-c选项将内容压缩到一行输出

apluser@FengYeHong-HP:~$ cat data2.json
{
  "id": 1,
  "name": "zhangsan",
  "score": [
    75,
    85,
    90
  ]
}
apluser@FengYeHong-HP:~$ cat data2.json | jq -c
{"id":1,"name":"zhangsan","score":[75,85,90]}

2.3-r

-r选项可以去掉字段两旁的"

apluser@FengYeHong-HP:~$ echo -n '{"id":1, "name":"zhangsan", "score":[75, 85, 90]}' | \
jq '.name' -r
zhangsan

2.4-R

把输入当作原始字符串处理（Raw Input），而不是默认的 JSON 结构。
sed 's/"//g'：将csv中的"给替换为空。
jq -R '[splits(",")]'：将逗号分隔的文本行转成数组。

apluser@FengYeHong-HP:~$ cat data.txt
"id","name","age","score"
"1","zhangsan","17","75"
"2","lisi","16","80"
"3","wangwu","18","85"
"4","zhaoliu","18","90"
apluser@FengYeHong-HP:~$ awk 'NR > 1' data.txt | sed 's/"//g' | jq -R '[splits(",")]'
[
  "1",
  "zhangsan",
  "17",
  "75"
]
[
  "2",
  "lisi",
  "16",
  "80"
]
[
  "3",
  "wangwu",
  "18",
  "85"
]
[
  "4",
  "zhaoliu",
  "18",
  "90"
]

三. 字段提取

3.1 普通字段

提取单个字段

apluser@FengYeHong-HP:~$ echo -n '{"id":1, "name":"zhangsan", "score":[75, 85, 90]}' | \
> jq '.name'
"zhangsan"

提取多个字段

apluser@FengYeHong-HP:~$ echo -n '{"id":1, "name":"zhangsan", "score":[75, 85, 90]}' | \
jq '.id, .name'
1
"zhangsan"

提取嵌套字段

apluser@FengYeHong-HP:~$ cat data3.json
{
  "name": "Alice",
  "age": 26,
  "city": "New York",
  "iwww.chinasem.cnnfo": {
    "sub_id": 10,
    "sub_address": "地球",
    "sub_num_list": [100, 200, 300]
  }
}
apluser@FengYeHong-HP:~$ cat data3.json | jq '.info.sub_address'
"地球"
# | 的管道符起到过滤作用
apluser@FengYeHong-HP:~$ cat data3.json | jq '.info | .sub_address'
"地球"

3.2 数组字段

提取数组字段中的指定元素，支持切片提取(类似于python的list语法)

apluser@FengYeHong-HP:~$ cat data3.json | jq '.info.sub_num_list[0]'
100
apluser@FengYeHong-HP:~$ cat data3.json | jq '.info.sub_num_list[1]'
200
apluser@FengYeHong-HP:~$ cat data3.json | jq '.info.sub_num_list[2]'
300
apluser@FengYeHong-HP:~$ cat data3.json | jq '.info.sub_num_list[0:2]'
[
  100,
  200
]

数组字段中的对象属性

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq '.items[].name'
"すてきな雑貨"
"格好いい置物"

apluser@FengYeHong-HP:~$ cat data1.json
[
  {
    "name": "Alice",
    "age": 25,
    "city": "New York"
  },
  {
    "name": "Bob",
    "age": 30,
    "city": "Los Angeles"
  },
  {
    "name": "Charlie",
    "age": 22,
    "city": "Chicago"
  }
]
apluser@FengYeHong-HP:~$
apluser@FengYeHong-HP:~$ cat data1.json | jq '.[] | .age'
25
30
22
apluser@FengYeHong-HP:~$ cat data1.json | jq '.[].age'
25
30
22

数组展开

apluser@FengYeHong-HP:~$ echo -n '[75, 85, 90]' | jq '.[]'
75
85
90

四. 编辑

4.1 字段更新

更新一个字段

apluser@FengYeHong-HP:~$ echo -n '{"name":"Alice","age":25,"city":"New York"}' | jq '.name = "贾飞天"'
{
  "name": "贾飞天",
  "age": 25,
  "city": "New York"
}

更新多个字段

apluser@FengYeHong-HP:~$ echo -n '{"name":"Alice","age":25,"city":"New York"}' | jq '. += {"name":"贾飞天", "age":26}'
{
  "name": "贾飞天",
  "age": 26,
  "city": "New York"
}

4.2 字段追加

追加一个字段

apluser@FengYeHong-HP:~$ echo -n '{"name":"Alice","age":25,"city":"New York"}' | jq '.country = "USA"'
{
  "name": "Alice",
  "age": 25,
  "city": "New York",
  "country": "USA"
}

追加一个字段的同时，修改既存的字段

apluser@FengYeHong-HP:~$ echo -n '{"name":"Alice","age":25,"city":"New York"}' | jq '.country = "USA" | .age = 50'
{
  "name": "Alice",
  "age": 50,
  "city": "New York",
  "country": "USA"
}

4.3 字段删除

删除一个字段

apluser@FengYeHong-HP:~$ echo -n '{"name":"Alice","age":25,"city":"New York"}' | jq 'del(.city)'
{
  "name": "Alice",
  "age": 25
}

4.4 转换为csv格式

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq .
{
  "items": [
    {
      "item_id": 1,
      "name": "すてきな雑貨",
      "price": 2500
    },
    {
      "item_id": 2,
      "name": "格好いい置物",
      "price": 4500
    },
    {
      "item_id": 3,
      "name": "ナイスなお皿",
      "price": 4500
    }
  ]
}
apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq '.items[] | [.item_id, .name, .price] | @csv' -r
1,"すてきな雑貨",2500
2,"格好いい置物",4500
3,"ナイスなお皿",4500

五. 过滤

5.1 字段整合

apluser@FengYeHong-HP:~$ echo '{"iteChina编程ms":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq '.items[] | { name: .name, yen: .price }'
{
  "name": "すてきな雑貨",
  "yen": 2500
}
{
  "name": "格好いい置物",
  "yen": 4500
}

5.2 select过滤

一个条件

apluser@FengYeHong-HP:~$ cat data1.json
[
  {
    "name": "Alice",
    "age": 25,
    "city": "New York"
  },
  {
    "name": "Bob",
    "age": 30,
    "city": "Los Angeles"
  },
  {
    "name": "Charlie",
    "age": 22,
    "city": "Chicago"
  }
]
apluser@FengYeHong-HP:~$ cat data1.json | jq '.[] | select(.age >= 25) | .name, .city'
"Alice"
"New York"
"Bob"
"Los Angeles"
apluser@FengYeHong-HP:~$ cat data1.json | jq '.[] | select(.age >= 25) | .name, .city' | paste -d "," - -
"Alice","New York"
"Bob","Los Angeles"

多个条件

apluser@FengYeHong-HP:~$ cat data1.json | jq '.[] | select(.age >= 25 and .age <= 30) | .name, .city' | sort
"Alice"
"Bob"
"Los Angeles"
"New York"

六. 函数

6.1 统计函数

6.1.1 add

apluser@FengYeHong-HP:~$ echo '1 2 3 4' | jq -s 'add'
10
apluser@FengYeHong-HP:~$ seq 4 | jq -s 'add'
10

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq '[.items[].price]'
[
  2500,
  4500
]
apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq '[.items[].price] | add'
7000

6.1.2 map

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq '.items | map({ name: .name, yen: .price })'
[
  {
    "name": "すてきな雑貨",
    "yen": 2500
  },
  {
    "name": "格好いい置物",
    "yen": 4500
  }
]

apluser@FengYeHong-HP:~$ seq 4 | jq -s 'map(tostring) | join(",")'
"1,2,3,4"

6.1.3 reduce

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | jq '.items[]'
{
  "item_id": 1,
  "name": "すてきな雑貨",
  "price": 2500
}
{
  "item_id": 2,
  "name": "格好いい置物",
  "price": js4500
}
apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500}]}' | \
jq 'reduce .items[] as $item (0; . + $item.price)'
7000

6.1.4 unique

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq '[.items[].price]'
[
  2500,
  4500,
  4500
]
apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いいwww.chinasem.cn置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq '[.items[].price] | unique'
[
  2500,
  4500
]

6.1.5 length

apluser@FengYeHong-HP:~$ echo '{"items":[{"item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq '.items'
[
  {
    "item_id": 1,
    "name": "すてきな雑貨",
    "price": 2500
  },
  {
    "item_id": 2,
    "name": "格好いい置物",
    "price": 4500
  },
  {
    "item_id": 3,
    "name": "ナイスなお皿",
    "price": 4500
  }
]
apluser@FengYeHong-HP:~$ echo '{"items":[{"编程China编程item_id":1,"name":"すてきな雑貨","price":2500},{"item_id":2,"name":"格好いい置物","price":4500},{"item_id":3,"name":"ナイスなお皿","price":4500}]}' | \
jq '.items | length'
3

6.2 字符串函数

6.2.1 contains

apluser@FengYeHong-HP:~$ echo hello | jq -R 'contains("he")'
true

6.2.2startswith/endswith

apluser@FengYeHong-HP:~$ echo hello | jq -R 'startswith("he")'
true

apluser@FengYeHong-HP:~$ echo hello | jq -R 'endswith("llo")'
true

6.2.3ltrimstr/rtrimstr

apluser@FengYeHong-HP:~$ echo ' hello ' | jq -R 'ltrimstr(" ") | rtrimstr(" ")' -r
hello

6.2.4 大小写转换

apluser@FengYeHong-HP:~$ echo hello | jq -R 'ascii_downcase' -r
hello
apluser@FengYeHong-HP:~$ echo hello | jq -R 'ascii_upcase' -r
HELLO

6.2.5 json对象与json字符串转换

json字符串　⇒　json对象

apluser@FengYeHong-HP:~$ echo -n '{"id":1,"name":"zhangsan","age":"17","attr":"{\"weight\":56,\"height\":178}"}' | \
jq '.attr = (.attr|fromjson)'
{
  "id": 1,
  "name": "zhangsan",
  "age": "17",
  "attr": {
    "weight": 56,
    "height": 178
  }
}

json对象　⇒　json字符串

apluser@FengYeHong-HP:~$ echo -n '{"id":1,"name":"zhangsan","age":"17","attr":{"weight":56,"height":178}}' | \
jq '.attr = (.attr|tojson)'
{
  "id": 1,
  "name": "zhangsan",
  "age": "17",
  "attr": "{\"weight\":56,\"height\":178}"
}
apluser@FengYeHong-HP:~$ echo -n '{"id":1,"name":"zhangsan","age":"17","attr":{"weight":56,"height":178}}' | \
jq '.attr = (.attr|tojson)' -c
{"id":1,"name":"zhangsan","age":"17","attr":"{\"weight\":56,\"height\":178}"}

6.3 字段

apluser@FengYeHong-HP:~$ cat data3.json
{
  "name": "Alice",
  "age": 26,
  "city": "New York",
  "info": {
    "sub_id": 10,
    "sub_address": "地球",
    "sub_num_list": [100, 200, 300]
  }
}

6.3.1 keys

获取所有key

apluser@FengYeHong-HP:~$ cat data3.json | jq '. | keys'
[
  "age",
  "city",
  "info",
  "name"
]

6.3.2 values

获取所有value
※jq-1.6的.values方法不好用，此处用[.[]]开替代

apluser@FengYeHong-HP:~$ jq --version
jq-1.6
apluser@FengYeHong-HP:~$ cat data3.json | jq '[.[]]'
[
  "Alice",
  26,
  "New York",
  {
    "sub_id": 10,
    "sub_address": "地球",
    "sub_num_list": [
      100,
      200,
      300
    ]
  }
]

6.3.3 to_entries

转换为键值对数组

apluser@FengYeHong-HP:~$ cat data3.json | jq '. | to_entries'
[
  {
    "key": "name",
    "value": "Alice"
  },
  {
    "key": "age",
    "value": 26
  },
  {
    "key": "city",
    "value": "New York"
  },
  {
    "key": "info",
    "value": {
      "sub_id": 10,
      "sub_address": "地球",
      "sub_num_list": [
        100,
        200,
        300
      ]
    }
  }
]

七. 排序

排序之前

apluser@FengYeHong-HP:~$ echo '[{"name": "Tom", "age": 25},{"name": "Jerry", "age": 18},{"name": "Alice", "age": 30}]' | jq
[
  {
    "name": "Tom",
    "age": 25
  },
  {
    "name": "Jerry",
    "age": 18
  },
  {
    "name": "Alice",
    "age": 30
  }
]

按照指定字段(age) 升序排序

apluser@FengYeHong-HP:~$ echo '[{"name": "Tom", "age": 25},{"name": "Jerry", "age": 18},{"name": "Alice", "age": 30}]' | \
jq 'sort_by(.age)'
[
  {
    "name": "Jerry",
    "age": 18
  },
  {
    "name": "Tom",
    "age": 25
  },
  {
    "name": "Alice",
    "age": 30
  }
]

按照指定字段(age) 降序排序

apluser@FengYeHong-HP:~$ echo '[{"name": "Tom", "age": 25},{"name": "Jerry", "age": 18},{"name": "Alice", "age": 30}]' | \
jq 'sort_by(.age) | reverse'
[
  {
    "name": "Alice",
    "age": 30
  },
  {
    "name": "Tom",
    "age": 25
  },
  {
    "name": "Jerry",
    "age": 18
  }
]

总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持China编程(www.chinasem.cn)。

这篇关于Linux jq命令的使用解读的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！

Linux jq命令的使用解读

目录

一. 简介

二. 选项

2.1.

2.2-c

2.3-r

2.4-R

三. 字段提取

3.1 普通字段

3.2 数组字段

四. 编辑

4.1 字段更新

4.2 字段追加

4.3 字段删除

4.4 转换为csv格式

五. 过滤

5.1 字段整合

5.2 select过滤

六. 函数

6.1 统计函数

6.1.1 add

6.1.2 map

6.1.3 reduce

6.1.4 unique

6.1.5 length

6.2 字符串函数

6.2.1 contains

6.2.2startswith/endswith

6.2.3ltrimstr/rtrimstr

6.2.4 大小写转换

6.2.5 json对象与json字符串转换

6.3 字段

6.3.1 keys

6.3.2 values

6.3.3 to_entries

七. 排序

总结

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