JQ

jq is a library written in C and produces functionalities like sed for JSON data.
JSON is getting popular and used in various applications and many a time, developers or applications have to parse or read through JSON data or files.
JQ comes very handy in these cases.

Let’s install it

We can install using below commands
Linux: sudo apt-get install jq
OSX: brew install jq
Windows: chocolatey install jq

 

 

Let’s see if it is installed

Run below command, and it should show the version details

jq –version
jq-1.5

 

 

Lets see jq in action:

 

Print a simple json data

sample='[{“firstname”:”john”},{“lastname”:”dow”}]’
echo “${sample}” | jq ‘.’

Output:
[
{
“firstname”: “john”
},
{
“lastname”: “dow”
}
]

echo “${sample}” | jq ‘.[0].firstname’
Output
john

Lets create a JSON file.
create data.json with below contents
[
{
“Data”: {
“Name”: “test”,
“DB”: {
“first”: {
“url”: “http://test…./123”,
“port”: “5123”
},
“second”: {
“url”: “http://test…./124”,
“port”: “5122”
}
}

}
}
]

Now lets parse it

echo jq ‘.[] | .Data.DB.first.url’ data.json
Output:
“http://test…./123”

So we can parse json data or files and extract information/data that is required.

Please refer jq main page for more details https://stedolan.github.io/jq/