Linux command Details (11) Shell parsing JSON command JQ detailed

Preface

In an automated deployment involving shell scripts requires dynamic reading of many configuration files, preferably in JSON format.

More JQ information: http://stedolan.github.io/jq/manual/

First, the value is obtained by key

Syntax:jq '. Key '

1, single value acquisition

Cat ' . Sign ' " d25341478381063d1c76e81b3a52e0592a7c997f "

2. JSON nested parse (nested parsing)

Cat ' . Live_node_config.node1.ip ' " 192.168.10.10 "

Note: The key name of the JSON array must be an underscore "_" and cannot be "-", otherwise it cannot be resolved. Such as:

Name of the error

  "Live-node-proxy-config": {    "IP":"192.168.10.100",    "User":"www",    "pwd":"www123456"  },

That's right

  "Live_node_proxy_config": {    "IP":"192.168.10.100",    "User":"www",    "pwd":"www123456"  },

Small chopper!!! Here we can use curl to get exactly the same results

' https://www.tinywan.com/frontend/websocket_client/autoInstallConf ' ' . Live_node_config.node1.ip ' " 192.168.10.10 "

The-s parameter of Curl indicates: silent mode. Don't output anything, learn more about the "Curl command"

If you do not add this parameter here, the file download progress will be output as follows:

[Email protected]:~$ Curl'https://www.tinywan.com/frontend/websocket_client/autoInstallConf'| Jq'. Live_node_config.node1.ip'% Total% Received%xferd Average Speed time time dload Upload Total spent left Speed -   636    0   636    0     0   2053      0--:--:-- --:--:-- --:--:--2058"192.168.10.10"

3. Parse non-existent element, will return null

Cat ' . live_node_config.node1.ip123 ' NULL

The built-in functions of the JQ, such as: Keys,has

1. Keys is used to get the key element in the JSON, find all the keys in the JSON

[Email protected]:$ Curl'https://www.tinywan.com/frontend/websocket_client/autoInstallConf'| Jq'Keys'[  "Live-node-config",  "Live-node-proxy-config",  "Osscmd-config",  "Push-config",  "Redis-config",  " Sign"]

2. Has is used to determine if there is a key

' https://www.tinywan.com/frontend/websocket_client/autoInstallConf ' ' Have ("sign") ' true [email protected]: ' https://www.tinywan.com/frontend/websocket_client/autoInstallConf ' ' Has ("sign2") ' false [email protected]:~$

Detailed description of the Linux command (11) Shell parsing JSON command JQ detailed