brew install jq

sudo apt-get install jq

sudo pacman -S jq

docker run --rm -i ghcr.io/jqlang/jq < input.json

# 基本语法
jq '.' input.json

# 管道输入
cat input.json | jq '.'
echo '{"name":"张三","age":30}' | jq '.'

{
  "name": "张三",
  "age": 30,
  "skills": ["Python", "Go", "Rust"],
  "address": {
    "city": "北京",
    "district": "朝阳区"
  }
}

# 访问姓名
echo '{"name":"张三"}' | jq '.name'
# 输出: "张三"

# 访问城市
echo '{"address":{"city":"北京"}}' | jq '.address.city'
# 输出: "北京"

# 访问数组元素
echo '["a","b","c"]' | jq '.[0]'
# 输出: "a"

# 展开数组
echo '["a","b","c"]' | jq '.[]'
# 输出:
# "a"
# "b"
# "c"

# 数组切片
echo '[1,2,3,4,5]' | jq '.[0:3]'
# 输出: [1, 2, 3]

# 数组长度
echo '[1,2,3]' | jq 'length'
# 输出: 3

# 数组包含
echo '[1,2,3]' | jq 'contains([2])'
# 输出: true

# 获取所有键
echo '{"a":1,"b":2}' | jq 'keys'
# 输出: ["a", "b"]

# 获取所有值
echo '{"a":1,"b":2}' | jq 'values'
# 输出: [1, 2]

# 获取键值对
echo '{"a":1,"b":2}' | jq 'to_entries'
# 输出: [{"key":"a","value":1},{"key":"b","value":2}]

# 对象合并
echo '{"a":1}' | jq '. + {"b":2}'
# 输出: {"a":1,"b":2}

# 删除键
echo '{"a":1,"b":2}' | jq 'del(.a)'
# 输出: {"b":2}

# 链式调用
echo '{"user":{"name":"张三","age":30}}' | jq '.user.name'
# 输出: "张三"

# 嵌套访问
echo '{"users":[{"name":"A"},{"name":"B"}]}' | jq '.users[].name'
# 输出:
# "A"
# "B"

# 算术运算
echo '5' | jq '. + 3'      # 加法: 8
echo '10' | jq '. - 4'      # 减法: 6
echo '6' | jq '. * 7'       # 乘法: 42
echo '10' | jq '. / 2'      # 除法: 5
echo '7' | jq '. % 3'       # 取模: 1

# 比较运算
echo '5' | jq '5 > 3'       # true
echo '5' | jq '5 >= 5'      # true
echo '"abc"' | jq '"abc" == "abc"'  # true

# if-then-else
echo '5' | jq 'if . > 3 then "大" else "小" end'
# 输出: "大"

# 多条件
echo '7' | jq 'if . < 3 then "小" elif . < 7 then "中" else "大" end'
# 输出: "大"

# and/or/not
echo '5' | jq 'if . > 3 and . < 10 then "在范围内" else "超出范围" end'
# 输出: "在范围内"

# 字符串函数
echo '"hello"' | jq 'upcase'
# 输出: "HELLO"

echo '"  hello  "' | jq 'trim'
# 输出: "hello"

echo '"hello"' | jq 'split("")'
# 输出: ["h", "e", "l", "l", "o"]

# 数值函数
echo '3.14159' | jq 'floor'    # 3
echo '3.14159' | jq 'ceil'     # 4
echo '3.6' | jq 'round'         # 4

# 数组函数
echo '[1,2,3]' | jq 'sort'      # [1,2,3]
echo '[3,1,2]' | jq 'sort'       # [1,2,3]
echo '[1,2,3]' | jq 'reverse'     # [3,2,1]
echo '[1,2,3]' | jq 'unique'     # [1,2,3]
echo '[1,1,2,2,3]' | jq 'unique'  # [1,2,3]

# 对象函数
echo '{"b":2,"a":1}' | jq 'sort_by(.a)'
# 输出: [{"a":1,"b":2}]
echo '[{"n":"b"},{"n":"a"}]' | jq 'sort_by(.n)'
# 输出: [{"n":"a"},{"n":"b"}]

# select - 条件筛选
echo '[1,2,3,4,5]' | jq 'map(select(. > 2))'
# 输出: [3, 4, 5]

# map - 批量转换
echo '[1,2,3]' | jq 'map(. * 2)'
# 输出: [2, 4, 6]

# flatten - 扁平化
echo '[[1,2],[3,4]]' | jq 'flatten'
# 输出: [1, 2, 3, 4]

# group_by - 分组
echo '[{"type":"a","v":1},{"type":"b","v":2},{"type":"a","v":3}]' | jq 'group_by(.type)'
# 输出: [[{"type":"a","v":1},{"type":"a","v":3}],[{"type":"b","v":2}]]

# any/all - 逻辑判断
echo '[true,false,true]' | jq 'any'  # true
echo '[true,false,false]' | jq 'all'  # false

# GitHub API响应
curl -s https://api.github.com/repos/jqlang/jq | jq '{stars: .stargazers_count, forks: .forks_count, name: .full_name}'

# 提取多个字段
curl -s 'https://httpbin.org/json' | jq '.slideshow.slides[] | {title: .title, type: .type}'

# 解析JSON日志
cat app.log | jq -r '.timestamp + " " + .level + " " + .message'

# 过滤错误级别
cat app.log | jq -c 'select(.level == "ERROR")'

# 统计每种级别数量
cat app.log | jq -r '.level' | sort | uniq -c

# 读取配置值
cat config.json | jq '.database.host'

# 修改配置值（不修改原文件）
cat config.json | jq '.port = 8080'

# 合并配置
jq -s '.[0] * .[1]' base.json override.json

# CSV转JSON
cat data.csv | tail -n +2 | while IFS=',' read -r name age city; do
  echo "{\"name\":\"$name\",\"age\":\"$age\",\"city\":\"$city\"}"
done | jq -s '.'

# JSON转CSV
jq -r '.[] | [.name, .age, .city] | @csv' data.json

# JSON转TSV
jq -r '.[] | [.name, .age] | @tsv' data.json

# 复杂数据处理
curl -s https://api.github.com/repos/jqlang/jq/commits | \
  jq '[.[] | {message: .commit.message, author: .commit.author.name, date: .commit.author.date}]' | \
  jq 'sort_by(.date) | reverse | .[0:5]'

# 紧凑JSON输出
echo '{"a":1,"b":2}' | jq -c '.'
# 输出: {"a":1,"b":2}

# 原始字符串输出
echo '"hello"' | jq -r '.'
# 输出: hello

# 传入变量
NAME="张三"
echo '{}' | jq --arg name "$NAME" '.name = $name'
# 输出: {"name":"张三"}

# 读取过滤程序文件
echo '{"test":true}' | jq -f filter.jq

# 在过滤程序中定义函数
echo '5' | jq 'def is_even: . % 2 == 0; is_even'
# 输出: false

# 递归函数
echo '5' | jq 'def fact: if . <= 1 then 1 else . * (. - 1 | fact) end; fact'
# 输出: 120

# 使用模块
jq -L '~/.jq/lib' 'include "mylib"; myfunc'

# 导入远程模块 (需要网络)
jq -s 'import "stdlib" as std; std::round(.temperature)'

# 正则匹配
echo '"hello world"' | jq 'test("^hello")'
# 输出: true

# 正则替换
echo '"hello world"' | jq 'gsub("world"; "jq")'
# 输出: "hello jq"

# 正则提取
echo '"item123price456"' | jq '[match("[0-9]+"; "g")] | map(.string)'
# 输出: ["123", "456"]

# jq (一行命令)
echo '{"name":"张三"}' | jq '.name'

# Python (需要多行)
python3 -c "import json,sys; print(json.load(sys.stdin)['name'])"