1. 简介
json是一种轻量级的数据交换格式，应用范围非常广泛。在Linux系统下使用jq工具可以非常方便的处理json，官方给的定义是：
A jq program is a “filter”: it takes an input, and produces an output. There are a lot of builtin filters for extracting a particular field of an object, or converting a number to a string, or various other standard tasks.
通俗的说就是一个能够接受json，处理json，输出json的程序，反正很好用。
安装起来也非常的方便，直接使用yum即可安装。
[root@test-dhcp ~]# yum install jq
2. 基本操作
创建
[root@test-dhcp ~]# jq -n {a:1}{"a": 1}[root@test-dhcp ~]# jq -n '{a:"test"}'{"a":"test"}
合并
[root@test-dhcp ~]# jq -n '{a:"test"} + {b:2}'{"a":"test","b": 2}[root@test-dhcp ~]# jq -n '{a:"test"} + {b:2} + {c:"testc"}'{"a":"test","b": 2,"c":"testc"}
删除
[root@test-dhcp ~]# cat test.json {"a":"test","b": 2,"c":"testc"}[root@test-dhcp ~]# cat test.json |jq .{"a":"test","b": 2,"c":"testc"}[root@test-dhcp ~]# cat test.json |jq 'del(.b)'{"a":"test","c":"testc"}
更新
[root@test-dhcp ~]# cat test.json {"a":"test","b": 2,"c":"testc"}[root@test-dhcp ~]# cat test.json |jq '.b="testb"'{"a":"test","b":"testb","c":"testc"}[root@test-dhcp ~]# cat test.json |jq '. + {d:4}'{"a":"test","b": 2,"c":"testc","d": 4}[root@test-dhcp ~]# cat test.json |jq '. + {d:4}' |jq '.d={dd:5}'{"a":"test","b": 2,"c":"testc","d": {"dd": 5 }}
查询
[root@test-dhcp ~]# cat test.json |jq .{"a":"test","b": 2,"c":"testc","d": {"dd": 5 }}[root@test-dhcp ~]# cat test.json |jq '. + {d:4}' |jq '.d={dd:5}' |jq .d.dd5[root@test-dhcp ~]# echo '{"a":1,"b":2}' |jq '[.a,.b]'[ 1, 2]
查看数据类型
[root@test-dhcp ~]# echo "{}" |jq -r typeobject[root@test-dhcp ~]# echo '[0, false, [], {}, null, "hello"]' |jq 'map(type)'["number","boolean","array","object","null","string"]
查询数组中的值
[root@test-dhcp ~]# echo [1,2,3] |jq .[1]2[root@test-dhcp ~]# echo [1,2,3] |jq .[2]3
查询数组长度
[root@test-dhcp ~]# echo [1,2,3,9] |jq '.|length'4[root@test-dhcp ~]# echo [1,2,3] |jq '.|length'3
数组相加
[root@test-dhcp ~]# echo [1,2,3] |jq '. + [4,5,6]'[ 1, 2, 3, 4, 5, 6]
高级查询
[root@test-dhcp ~]# echo [1,2,3] | jq 'map(select(. >= 2))'[ 2, 3][root@test-dhcp ~]# echo [1,2,3] | jq 'map(select(. == 2))'[ 2][root@test-dhcp ~]# echo [1,2,3] | jq 'map(select(. != 2))'[ 1, 3][root@test-dhcp ~]# cat test.json [ {"id":"0","model":"Intel(R)Xeon(R)CPUE5-2620v4@2.10GHz"}, {"id":"1","model":"Intel(R)Xeon(R)CPUE5-2620v4@2.10GHz"}][root@test-dhcp ~]# cat test.json |jq .[].model"Intel(R)Xeon(R)CPUE5-2620v4@2.10GHz""Intel(R)Xeon(R)CPUE5-2620v4@2.10GHz"
类型转换
[root@test-dhcp ~]# echo '["a","b,c,d","e"]' |jq 'join(",")'"a,b,c,d,e"[root@test-dhcp ~]# echo '["a","b,c,d","e",1]' |jq 'join(",")'jq: error (at :1): string (",") and number (1) cannot be added[root@test-dhcp ~]# cat test.json liuxin,30,malejiaweiqiang,29,femal[root@test-dhcp ~]# jq -R 'split(",")|{"name":.[0],"age":.[1],"sex":.[2]}' ./test.json{"name":"liuxin","age":"30","sex":"male"}{"name":"jiaweiqiang","age":"29","sex":"femal"}[root@test-dhcp ~]# cat test.json {"name":"liuxin","age":"30","sex":"male"}{"name":"jiaweiqiang","age":"29","sex":"femal"}[root@test-dhcp ~]# cat test.json |jq . -c{"name":"liuxin","age":"30","sex":"male"}{"name":"jiaweiqiang","age":"29","sex":"femal"}
3. 总结
作者：小小运维
链接：https://www.jianshu.com/p/3522fe70de19
来源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。
