How to parse a system(curl) response into workspace variables

Hello- Can anyone provide some insight into how to properly parse the system(curl) response into matlab.

It is currently returned into a string field, but I need to get the individual name/value pairs as variables.

No doubt there is a better way to make this request using webread, but I have been unsuccessful in formatting the headers properly, so have been using curl.

The objective is to pull these two pairs and save them as seperate variables in matlab

"access_token" : "n0f9jeyyc"

"expires_in" : 1800

The system(curl) request (with token abbreviated)

>>>>>>>

command = 'curl -X POST --header "Content-Type: application/x-www-form-urlencoded" -d "grant_type=refresh_token&refresh_token=uc80SIH3400B75E&access_type=&code=&client_id=CPUNQFIRUX1FHKWW8XJO7DMZWRCRQGMU%40AMER.OAUTHAP&redirect_uri=http%3A%2F%2Flocalhost" "https://api.tdameritrade.com/v1/oauth2/token"';

[response, curl_response] = system(command);

>>>>>>>

The response which is placed in one large string;

%%%%%

curl_response =

' % Total % Received % Xferd Average Speed Time Time Time Current

Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0

100 2636 100 1489 100 1147 5304 4086 --:--:-- --:--:-- --:--:-- 9448

{

"access_token" : "n0f9jeyyc",

"scope" : "PlaceTrades AccountAccess MoveMoney",

"expires_in" : 1800,

"token_type" : "Bearer"

}'

%%%%%

Answer 1

[Poorna]

Hello Dwayne,

I understand that you are looking to parse the response returned by the “system” function after running the cURL command and extract the values of "access_token" and "expires_in".

You can follow the below steps to achieve this:

• Use the “regexp” function to extract the JSON portion from the “curl_response” string. This can be done by searching for the pattern enclosed within curly braces.

jsonStr = regexp(curl_response, '{.*}', 'match', 'once'); 

• Next, utilize the “jsondecode” function to parse the extracted JSON string and convert it into a MATLAB struct.

jsonData = jsondecode(jsonStr); 

• Finally, access the individual name/value pairs ("access_token" and "expires_in") from the parsed JSON data using the dot operator.

% Access the individual name/value pairs as variables 
access_token = jsonData.access_token; 
expires_in = jsonData.expires_in;

Please refer to the following documentation for more information on the functions used:

regexp: https://www.mathworks.com/help/matlab/ref/regexp.html

jsondecode: https://www.mathworks.com/help/matlab/ref/jsondecode.html

Hope this Helps!