In Powershell, how do I pull specific text from an object that was returned by an API response?

Question

New to Powershell here so any advice is appreciated. I'm Posting to this website's API (I code-named it authenticate.com in the below code) to receive in the response an auth token as a cookie. The next objective is to take the cookie and use it to validate to a different API? How can I capture the auth-token returned by the first API and save it into a variable?

My code:

$Url = 'https://authenticate.com/apikeylogin'
$auth = @{
     keyPublic= '********************'
     keySecret= '********************'
}
$json = $auth | ConvertTo-Json
$response = Invoke-WebRequest $Url -Method Post -Body $json -ContentType 'application/json'
$response | Get-Member
$response.RawContent

The response in raw-text:

HTTP/1.1 200 OK
auth-token: ******************
[Below this is are a dozen more lines of raw data]

To restate the question, how do I get the above value of 'auth-token' and store it into a variable?

Answer 1

You can use Select-String (similar to grep in powershell) to figure out the line containing the auth-token and get the auth-token value.

$response = "HTTP/1.1 200 OK `
auth-token: ABCDEFGHIJKLMNOP `
[Below this is are a dozen more lines of raw data]"

$authTokenline =
 $response.Split("`n") | Select-String -Pattern "^auth-token:.*$" 
$authToken = $authTokenline.ToString().Split(":")[1]

ABCDEFGHIJKLMNOP

Answer 2

Ok, I have solved the problem using.Substring()

$auth = @{
     keyPublic= '********************'
     keySecret= '********************'
}
$json = $auth | ConvertTo-Json
$response = Invoke-WebRequest $Url -Method Post -Body $json -ContentType 'application/json'
$raw = $response.RawContent
$string = $raw | Out-String
$auth_token = $string.Substring(35, 90)

The access token I am requesting from the API always has the same length so I used the substring method to pinpoint exactly which chars from the string are what I need and then store them in the variable "auth-token"