linux下json文本解析工具：jq

前言

在linux環境下，對於json文本閱讀是相當麻煩的，jq處理則相當輕鬆。

例子

使用測試內容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. 獲取整個json內容
   . 過濾器直接將json內容簡單輸出
   [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. 獲取鍵"char"的值
   . 對指定鍵值過濾輸出
   [root@kilo-k5-controller baojx]# cat data.json |jq .char
   [
   “a”,
   “b”,
   “c”
   ]

3. 獲取鍵值array中指定索引的數據
   .[]
   [root@kilo-k5-controller baojx]# cat data.json |jq .char[2]
   “c”

4. 遍歷鍵值array中所有數據
   .[]
   [root@kilo-k5-controller baojx]# cat data.json |jq .char[]
   “a”
   “b”
   “c”
   *輸出三次

5. 遍歷字典（鍵值對）而非array
   5.1 遍歷鍵值對輸出效果同array遍歷，不同的是輸出數據僅爲鍵值對中的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 對鍵值對遍歷可以使用array指定索引類似的形式以獲取指定key的vaule
   [root@kilo-k5-controller baojx]# cat data.json |jq ‘.[“char”]’
   [
   “a”,
   “b”,
   “c”
   ]
   *這種操作有一個最大的好處是，當key含有特殊字符串不能直接使用"."進行過濾輸出時，可以用這種方法正常進行數據提取
   [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. 篩選出address中jiangsu的鍵值對
   [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”
   }