命令行中處理json數據

一、安裝

百度brew install、apt install、yum install等

二、常用操作

1.格式化json

XX命令  | jq    #比如cat a.json |jq

XX命令 | jq ''  #比如cat a.json | jq ''

cat a.json | jq '' | less    #如果 json 很長，則可以使用管道傳給 less 命令　

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
響應如下：
{
  "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指定所有字段，如{date, high}，獲取昨天的最高溫度如下

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

5.篩選數組

直接指定數組的索引即可

curl -s http://t.weather.sojson.com/api/weather/city/101310215 |jq ".data.forecast"|jq ".[0,9]"
響應如下：
{
  "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"
}