I am trying to get the amount of reputation that a user has

how to handle the response (or get one) from a script

You can do this with a Bash command that you can then embed in a script. Here's how:

1. Look up your user ID

Assuming you want to get the reputation on Stack Overflow, go to your account and look up your user ID in the URL:

https://stackoverflow.com/users/123456/your-name 

In this example, the ID is 123456.

2. Get user info

Make your first API call with curl:

curl --compressed https://api.stackexchange.com/2.2/users/123456/?site=stackoverflow 

This will print a single line of JSON data about you on Stack Overflow, including your reputation.

The --compressed flag makes curl uncompress the response which is compressed using gzip.

We can format the data using jq to make it easier to read:

curl --compressed https://api.stackexchange.com/2.2/users/123456/?site=stackoverflow | jq 

Given that you have jq installed, this will produce much nicer output:

{ "items": [ { "badge_counts": { "bronze": 122, "silver": 85, "gold": 11 }, "account_id": 999999, "is_employee": false, "last_modified_date": 1560547206, "last_access_date": 1562693872, "reputation_change_year": 2168, "reputation_change_quarter": 90, "reputation_change_month": 90, "reputation_change_week": 30, "reputation_change_day": 0, "reputation": 15343, "creation_date": 1306744511, "user_type": "registered", "user_id": 123456, "accept_rate": 85, "location": "Austria", "website_url": "https://www.you.com", "link": "https://stackoverflow.com/users/123456/your-name", "profile_image": "https://i.sstatic.net/SyKPw.jpg?s=128&g=1", "display_name": "Your Name" } ], "has_more": false, "quota_max": 300, "quota_remaining": 268 } 

3. Filter the data

Alright, now that we have the data, how do we get at just the user's reputation?

Using jq's filters:

curl --compressed https://api.stackexchange.com/2.2/users/123456/?site=stackoverflow | jq '.items[0].reputation' 

This will print the reputation of the user with ID 123456:

15343