下载地址：https://github.com/stedolan/jq/releases

# 放到/usr/local/bin下并改名方便命令调用

[root@rootop logs]# cd /usr/local/bin/
[root@rootop logs]# wget -c https://github.com/stedolan/jq/releases/download/jq-1.6/jq-linux64
[root@rootop logs]# mv jq-linux64 jq

# 格式化json串，格式化后是带颜色的，很方便阅读。注意后面是跟的 点 .

[root@rootop logs]# tail -f www.rootop.org.log | jq .
{
  "remote_addr": "66.249.75.44",
  "remote_user": "-",
  "time_local": "24/May/2019:16:08:05 +0800",
  "request": "GET /pages/category/serversafe/page/2 HTTP/1.1",
  "status": "200",
  "body_bytes_sent": "8852",
  "http_referer": "-",
  "user_agent": "Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.96 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
}

# 获取某个key的值，注意key前面有个点：

[root@rootop logs]# tail -f www.rootop.org.log | jq .user_agent
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36"

# 比如要在shell脚本中调用json中的某个值：

ua=`cat json_file | jq .user_agent`
echo $ua
这样就可以调到user_agent的值了。