How to Parse JSON in command line

Why parse JSON in command line

• for readable structuring data
• for easy understanding
• for efficacy less time

Solution

use jq, lightweight and flexible command-line JSON processor.

- Install jq

• Windows - via chocolatey

choco install jq
or 
chocolatey install jq

• Linux / Unix Like

#Debian / Ubuntu base
sudo apt-get update
sudo apt-get install jq

#RedHat / Fedora base
sudo dnf update
sudo dnf install jq

• Mac OS

brew update
brew install jq

- Sample Use-Case

With curl example

• format json use js '.'

 curl --location 'http://192.168.1.100/api/v4/projects/1/merge_requests/1/approvals' --header 'PRIVATE-TOKEN: <<YOUR TOKEN>>' | jq '.'

• Select property changes_count from json

NUM_MR_FILE=$(curl --location "$CI_API_V4_URL/projects/$CI_PROJECT_ID/merge_requests/$CI_MERGE_REQUEST_IID" --header "PRIVATE-TOKEN: $SECRET_GITLABINFO" | jq '.changes_count ')

echo $NUM_MR_FILE

• Convert Field changes_count from string to number (jq tonumber)

NUM_MR_FILE=$(curl --location "$CI_API_V4_URL/projects/$CI_PROJECT_ID/merge_requests/$CI_MERGE_REQUEST_IID" --header "PRIVATE-TOKEN: $SECRET_GITLABINFO" | jq '.changes_count | tonumber ')

echo $NUM_MR_FILE

• Select and Count from Array

NUM_APPROVE=$(curl --location "$CI_API_V4_URL/projects/$CI_PROJECT_ID/merge_requests/$CI_MERGE_REQUEST_IID/approvals" --header "PRIVATE-TOKEN: $SECRET_GITLABINFO" | jq '.approved_by | length')

echo $NUM_APPROVE

Other Example Here jq Manual (development version) (jqlang.github.io)

Reference

• jq (jqlang.github.io)