linux使用jq处理json数据

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linux json jq
  1. 格式化json
  2. 获取value
  3. 内建函数
    1. key获取JSON中的key元素

JSON是前端编程经常用到的格式，对于PHP或者Python，解析JSON都不是什么大事，尤其是PHP的json_encode和json_decode,干的相当的漂亮。Linux下也有处理处理JSON的神器：jq

格式化json

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$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null
{"code":0,"data":{"country":"\u4e2d\u56fd","country_id":"CN","area":"\u534e\u5317","area_id":"100000","region":"\u5317\u4eac\u5e02","region_id":"110000","city":"\u5317\u4eac\u5e02","city_id":"110100","county":"","county_id":"-1","isp":"\u8054\u901a","isp_id":"100026","ip":"202.106.0.20"}}

这样的数据大家看起来是不是非常的头疼，以前都是通过在线JSON格式化工具做的.
jq就可以检查JSON的合法性，并把JSON格式化成更友好更可读的格式

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$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq
{
  "code": 0,
  "data": {
    "country": "中国",
    "country_id": "CN",
    "area": "华北",
    "area_id": "100000",
    "region": "北京市",
    "region_id": "110000",
    "city": "北京市",
    "city_id": "110100",
    "county": "",
    "county_id": "-1",
    "isp": "联通",
    "isp_id": "100026",
    "ip": "202.106.0.20"
  }
}

现在是不是看着舒服多了,可阅读性明显增加了

获取value

获取value类似python，根据key获取value

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$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq '.code'
0
curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq '.data.country_id'
"CN" //嵌套解析
$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq '.codes'
null //解析不存在的元素，会返回null

内建函数

jq还有一些内建函数如 key，has

key获取JSON中的key元素

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$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq 'keys'
[
  "code",
  "data"
]
``` 
## has判断是否存在某个key

$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq ‘has(“data”)’
true

$ curl http://ip.taobao.com/service/getIpInfo.php?ip=202.106.0.20 2>/dev/null | jq ‘has(“datas”)’
false
`

###jq官网

###jq-github