Linux命令行操做json神器jq

jq相似一個awk或grep同樣的神器，能夠方便地在命令行操做json

這裏我使用海南萬寧的天氣接口作演示，地址：http://t.weather.sojson.com/api/weather/city/101310215

1、安裝

官網：https://stedolan.github.io/jq/download/
基本就是brew install、apt install、yum install之類的，很簡單

2、經常使用操做

1.格式化json

直接請求，格式明顯不易讀

➜  ~ curl -s http://t.weather.sojson.com/api/weather/city/101310215
{"message":"success感謝又拍雲(upyun.com)提供CDN贊助","status":200,"date":"20191025","time":"2019-10-25 11:17:41","cityInfo":{"city":"萬寧市","citykey":"101310215","parent":"海南","updateTime":"09:59"},"data":{"shidu":"92%","pm25":20.0,"pm10":49.0,"quality":"優","wendu":"25","ganmao":"各種人羣可自由活動","forecast":[{"date":"25","high":"高溫 29℃","low":"低溫 23℃","ymd":"2019-10-25","week":"星期五","sunrise":"06:35","sunset":"18:10","aqi":44,"fx":"無持續風向","fl":"<3級","type":"中雨","notice":"記得隨身攜帶雨傘哦"},{"date":"26","high":"高溫 29℃","low":"低溫 23℃","ymd":"2019-10-26","week":"星期六","sunrise":"06:35","sunset":"18:09","aqi":31,"fx":"無持續風向","fl":"<3級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"27","high":"高溫 29℃","low":"低溫 23℃","ymd":"2019-10-27","week":"星期日","sunrise":"06:36","sunset":"18:09","aqi":28,"fx":"無持續風向","fl":"<3級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"28","high":"高溫 30℃","low":"低溫 22℃","ymd":"2019-10-28","week":"星期一","sunrise":"06:36","sunset":"18:08","aqi":34,"fx":"東北風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"29","high":"高溫 27℃","low":"低溫 22℃","ymd":"2019-10-29","week":"星期二","sunrise":"06:36","sunset":"18:07","aqi":35,"fx":"東北風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"30","high":"高溫 27℃","low":"低溫 22℃","ymd":"2019-10-30","week":"星期三","sunrise":"06:37","sunset":"18:07","aqi":32,"fx":"無持續風向","fl":"<3級","type":"中雨","notice":"記得隨身攜帶雨傘哦"},{"date":"31","high":"高溫 29℃","low":"低溫 22℃","ymd":"2019-10-31","week":"星期四","sunrise":"06:37","sunset":"18:06","fx":"東北風","fl":"3-4級","type":"中雨","notice":"記得隨身攜帶雨傘哦"},{"date":"01","high":"高溫 25℃","low":"低溫 24℃","ymd":"2019-11-01","week":"星期五","sunrise":"06:38","sunset":"18:06","fx":"東北風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"02","high":"高溫 25℃","low":"低溫 24℃","ymd":"2019-11-02","week":"星期六","sunrise":"06:38","sunset":"18:05","fx":"東北風","fl":"4-5級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"03","high":"高溫 26℃","low":"低溫 24℃","ymd":"2019-11-03","week":"星期日","sunrise":"06:38","sunset":"18:05","fx":"東風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"04","high":"高溫 25℃","low":"低溫 24℃","ymd":"2019-11-04","week":"星期一","sunrise":"06:39","sunset":"18:04","fx":"東北風","fl":"<3級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"05","high":"高溫 28℃","low":"低溫 24℃","ymd":"2019-11-05","week":"星期二","sunrise":"06:39","sunset":"18:04","fx":"東南風","fl":"<3級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"06","high":"高溫 25℃","low":"低溫 21℃","ymd":"2019-11-06","week":"星期三","sunrise":"06:40","sunset":"18:04","fx":"東北風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"07","high":"高溫 23℃","low":"低溫 22℃","ymd":"2019-11-07","week":"星期四","sunrise":"06:40","sunset":"18:03","fx":"東北風","fl":"3-4級","type":"小雨","notice":"雨雖小，注意保暖別感冒"},{"date":"08","high":"高溫 25℃","low":"低溫 22℃","ymd":"2019-11-08","week":"星期五","sunrise":"06:41","sunset":"18:03","fx":"北風","fl":"3-4級","type":"多雲","notice":"陰晴之間，謹防紫外線侵擾"}],"yesterday":{"date":"24","high":"高溫 29℃","low":"低溫 23℃","ymd":"2019-10-24","week":"星期四","sunrise":"06:34","sunset":"18:10","aqi":27,"fx":"無持續風向","fl":"<3級","type":"多雲","notice":"陰晴之間，謹防紫外線侵擾"}}}

使用jq格式化，以下

curl -s http://t.weather.sojson.com/api/weather/city/101310215 | jq 
{
  "message": "success感謝又拍雲(upyun.com)提供CDN贊助",
  "status": 200,
  "date": "20191025",
  "time": "2019-10-25 10:27:28",
  "cityInfo": {
    "city": "萬寧市",
    "citykey": "101310215",
    "parent": "海南",
    "updateTime": "09:59"
  },
  "data": {
    "shidu": "92%",
    "pm25": 20,
    "pm10": 49,
    "quality": "優",
    "wendu": "25",
    "ganmao": "各種人羣可自由活動",
    "forecast": [
      {
        "date": "25",
        "high": "高溫 29℃",
        "low": "低溫 23℃",
        "ymd": "2019-10-25",
        "week": "星期五",
        "sunrise": "06:35",
        "sunset": "18:10",
        "aqi": 44,
        "fx": "無持續風向",
        "fl": "<3級",
        "type": "中雨",
        "notice": "記得隨身攜帶雨傘哦"
      },...

已經格式化過

2.取指定字段的值

直接輸入字段，使用.嵌套訪問，例如要獲取昨天的信息

curl -s http://t.weather.sojson.com/api/weather/city/101310215 | jq .data.yesterday
{
  "date": "24",
  "high": "高溫 29℃",
  "low": "低溫 23℃",
  "ymd": "2019-10-24",
  "week": "星期四",
  "sunrise": "06:34",
  "sunset": "18:10",
  "aqi": 27,
  "fx": "無持續風向",
  "fl": "<3級",
  "type": "多雲",
  "notice": "陰晴之間，謹防紫外線侵擾"
}

3.過濾指定字段

使用一個json指定全部字段，如{date, high}，獲取昨天的最高溫度以下

curl -s http://t.weather.sojson.com/api/weather/city/101310215 | jq .data.yesterday|jq "{date,high}"
{
  "date": "24",
  "high": "高溫 29℃"
}

4.獲取多個字段的值

使用逗號獲取多個

curl -s http://t.weather.sojson.com/api/weather/city/101310215 | jq .data.yesterday|jq ".date, .high"
"24"
"高溫 29℃"

5.篩選數組

直接指定數組的索引便可

curl -s http://t.weather.sojson.com/api/weather/city/101310215 |jq ".data.forecast"|jq ".[0,9]"
{
  "date": "25",
  "high": "高溫 29℃",
  "low": "低溫 23℃",
  "ymd": "2019-10-25",
  "week": "星期五",
  "sunrise": "06:35",
  "sunset": "18:10",
  "aqi": 44,
  "fx": "無持續風向",
  "fl": "<3級",
  "type": "中雨",
  "notice": "記得隨身攜帶雨傘哦"
}
{
  "date": "03",
  "high": "高溫 26℃",
  "low": "低溫 24℃",
  "ymd": "2019-11-03",
  "week": "星期日",
  "sunrise": "06:38",
  "sunset": "18:05",
  "fx": "東風",
  "fl": "3-4級",
  "type": "小雨",
  "notice": "雨雖小，注意保暖別感冒"
}

更多操做請參考官方文檔：https://stedolan.github.io/jq/manual/