linux 命令之jq

jq命令允许直接在命令行下对JSON进行操作，包括分片、过滤、转换等
JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。基于JavaScript(Standard ECMA-262 3rd Edition - December 1999)的一个子集
JSON 数据的书写格式是： 名称/对象。
JSON的结构基于两点

• “名称/值”的集合 ,在不同的语言中,它可以被理解为对象(object)，记录(record)，结构(struct)，字典(dictionary)，哈希表(hash table)，键列表(keyed list)等 .

• 值的有序列表 多数语言中被理解为数组(array)

  JSON的基础结构说明

• 对象是属性、值的集合。一个对象开始与”{” ,结束于”}”。每一个属性名和值间用”:”分隔。每个属性间用”，”分隔。
• 值可以是字符串，数字，逻辑值，数组，对象，null。
  数字：整数或浮点数
  字符串：在双引号中
  逻辑符：true和false
  数组：在方括号中
  对象：在花括号中
  null： 代表空

Ubuntu下的jq安装

apt-get install jq

jq命令的格式

jq [options] filter [files]
**options：**
--version：输出jq的版本信息并退出
--slurp/-s：读入整个输入流到一个数组。
--raw-input/-R：不作为JSON解析，将每一行的文本作为字符串输出到屏幕。
--null-input/ -n：不读取任何输入，过滤器运行使用null作为输入。一般用作从头构建JSON数据。
--compact-output /-c：使输出紧凑，而不是把每一个JSON对象输出在一行。
--colour-output / -C：打开颜色显示
--monochrome-output / -M：关闭颜色显示

--ascii-output /-a：指定输出格式为ASCII

-raw-output /-r ：如果过滤的结果是一个字符串，那么直接写到标准输出（去掉字符串的引号）

**filter：**
.   : 默认输出
.foo: 输出指定属性，foo代表属性。
.[foo] ：输出指定数组元素。foo代表数组下标。
.[]：输出指定数组中全部元素
， ：指定多个属性作为过滤条件时，用逗号分隔
| ： 将指定的数组元素中的某个属性作为过滤条件

**files：**
    JOSN格式文件。

用作示例的JOSN文件。

[{"hostCompany":"Beijing Autelan Technology","hostModel":"CS-VIC-2000-C","hostsn":"01010730b12014A00477","mac":"00:1F:64:CE:F3:8E","cpuModel":"MIPS 74Kc V4.12","cpuSN":"000000","memoryModel":"abcdefg","memorySN":"000000","boardSN":"01010730b12014A00477","networkCardMac":"00:1F:64:CE:F3:8F","lowFreModel":"AR9344","lowFreSN":"000000","hignFreModel":"AR9582","hignFreSN":"000000","gpsModel":"abcdefg","gpsSN":"000000","MEID_3g":"A000004E123ABD2","Company_3g":"ZTEMT INCORPORATED","modelOf3g":"MC271X","snOf3g":"A000004E123ABD2","iccid":"89860314400200885980","Operators":"CTCC","hardVersion":"1.20","firmwareVersion":"1.0.6.29"}]

示例：

$ jq . apinfo.json   
[
  {
    "firmwareVersion": "1.0.6.29",
    "hardVersion": "1.20",
    "Operators": "CTCC",
    "iccid": "DATA DATA",
    "snOf3g": "A000004E123ABD2",
    "modelOf3g": "MC271X",
    "Company_3g": "ZTEMT INCORPORATED",
    "MEID_3g": "A000004E123ABD2",
    "memorySN": "000000",
    "memoryModel": "abcdefg",
    "cpuSN": "000000",
    "cpuModel": "MIPS 74Kc V4.12",
    "mac": "00:1F:64:CE:F3:8E",
    "hostsn": "01010730b12014A00477",
    "hostModel": "CS-VIC-1999-C",
    "stCompany": "Beijing Autelan Technology",
    "boardSN": "01010730b12014A00477",
    "networkCardMac": "00:1F:64:CE:F3:8F",
    "lowFreModel": "AR9344",
    "lowFreSN": "000000",
    "hignFreModel": "AR9582",
    "hignFreSN": "000000",
    "gpsModel": "abcdefg",
    "gpsSN": "000000"
  }
]

jq .[] apinfo.json 
{
  "firmwareVersion": "1.0.6.29",
  "hardVersion": "1.20",
  "Operators": "CTCC",
  "iccid": "DATA DATA",
  "snOf3g": "A000004E123ABD2",
  "modelOf3g": "MC271X",
  "Company_3g": "ZTEMT INCORPORATED",
  "MEID_3g": "A000004E123ABD2",
  "memorySN": "000000",
  "memoryModel": "abcdefg",
  "cpuSN": "000000",
  "cpuModel": "MIPS 74Kc V4.12",
  "mac": "00:1F:64:CE:F3:8E",
  "hostsn": "01010730b12014A00477",
  "hostModel": "CS-VIC-1999-C",
  "stCompany": "Beijing Autelan Technology",
  "boardSN": "01010730b12014A00477",
  "networkCardMac": "00:1F:64:CE:F3:8F",
  "lowFreModel": "AR9344",
  "lowFreSN": "000000",
  "hignFreModel": "AR9582",
  "hignFreSN": "000000",
  "gpsModel": "abcdefg",
  "gpsSN": "000000"
}

$ jq -r .[].mac apinfo.json 
00:1F:64:CE:F3:8E

$ jq -r '.[] | .mac' apinfo.json 
00:1F:64:CE:F3:8E

$ jq -r '.[] |.mac, .gpsSN' apinfo.json 
00:1F:64:CE:F3:8E
000000

jq -r '.[].mac, .[].gpsSN' apinfo.json 
00:1F:64:CE:F3:8E
000000