linux下json文本解析工具：jq

前言

在linux环境下，对于json文本阅读是相当麻烦的，jq处理则相当轻松。

例子

使用测试内容data.json
[root@kilo-k5-controller baojx]# cat data.json
{
“char”: [“a”, “b”, “c”],
“data:info”: {
“bob”: {
“address”: “jiangsu-nanjing”,
“wage”: “10000”
},
“sam”: {
“address”: “jiangsu-taizhou”,
“wage”: “15000”
},
“rollyd”: {
“address”: “shanghai-jingan”,
“wage”: “20000”
}
}
}

1. 获取整个json内容
   . 过滤器直接将json内容简单输出
   [root@kilo-k5-controller baojx]# cat data.json |jq .
   {
   “data:info”: {
   “rollyd”: {
   “wage”: “20000”,
   “address”: “shanghai-jingan”
   },
   “sam”: {
   “wage”: “15000”,
   “address”: “jiangsu-taizhou”
   },
   “bob”: {
   “wage”: “10000”,
   “address”: “jiangsu-nanjing”
   }
   },
   “char”: [
   “a”,
   “b”,
   “c”
   ]
   }

2. 获取键"char"的值
   . 对指定键值过滤输出
   [root@kilo-k5-controller baojx]# cat data.json |jq .char
   [
   “a”,
   “b”,
   “c”
   ]

3. 获取键值array中指定索引的数据
   .[]
   [root@kilo-k5-controller baojx]# cat data.json |jq .char[2]
   “c”

4. 遍历键值array中所有数据
   .[]
   [root@kilo-k5-controller baojx]# cat data.json |jq .char[]
   “a”
   “b”
   “c”
   *输出三次

5. 遍历字典（键值对）而非array
   5.1 遍历键值对输出效果同array遍历，不同的是输出数据仅为键值对中的value
   [root@kilo-k5-controller baojx]# cat data.json |jq .[]
   {
   “rollyd”: {
   “wage”: “20000”,
   “address”: “shanghai-jingan”
   },
   “sam”: {
   “wage”: “15000”,
   “address”: “jiangsu-taizhou”
   },
   “bob”: {
   “wage”: “10000”,
   “address”: “jiangsu-nanjing”
   }
   }
   [
   “a”,
   “b”,
   “c”
   ]
   5.2 对键值对遍历可以使用array指定索引类似的形式以获取指定key的vaule
   [root@kilo-k5-controller baojx]# cat data.json |jq ‘.[“char”]’
   [
   “a”,
   “b”,
   “c”
   ]
   *这种操作有一个最大的好处是，当key含有特殊字符串不能直接使用"."进行过滤输出时，可以用这种方法正常进行数据提取
   [root@kilo-k5-controller baojx]# cat data.json |jq ‘.data:info’
   error: syntax error, unexpected ‘:’, expecting $end
   .data:info
   ^
   1 compile error

[root@kilo-k5-controller baojx]# cat data.json |jq ‘.“data:info”’
error: syntax error, unexpected QQSTRING_START, expecting $end
.“data:info”
^
1 compile error

[root@kilo-k5-controller baojx]# cat data.json |jq ‘.[“data:info”]’
{
“rollyd”: {
“wage”: “20000”,
“address”: “shanghai-jingan”
},
“sam”: {
“wage”: “15000”,
“address”: “jiangsu-taizhou”
},
“bob”: {
“wage”: “10000”,
“address”: “jiangsu-nanjing”
}
}

6. 筛选出address中jiangsu的键值对
   [root@kilo-k5-controller baojx]# cat data.json |jq ‘.[“data:info”][]|select(.address|contains(“jiangsu”))’
   {
   “wage”: “15000”,
   “address”: “jiangsu-taizhou”
   }
   {
   “wage”: “10000”,
   “address”: “jiangsu-nanjing”
   }