How to differentiate Invoke-WebRequest exception (HTTP error code) in try catch statement

Question

I've created a script to download specific files on the Internet with a PowerShell script using the Invoke-WebRequest cmdlet.

I've 2 known exception I would like to handle: 404 and 429.

I'm currently working with a try/catch statement:

try {
    Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} catch {
    ...snip...
}

But for both errors, I've the same code and it's not what I would like to do:

try {
    Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} catch [something here] {
    # Here the code I would like to write if the HTTP response is 404 File not found
    # Will certainly be a continue command
} catch [something here] {
    # Here the code I would like to write if the HTTP response is 429 Too many request
    # Will certainly be a sleep command for 1 hour
}

Here the output of the command in both situation:

Error HTTP 404
Invoke-WebRequest : The remote server returned an error : (404) Not Found.
At line:1 char:1
+ Invoke-WebRequest -Uri https://<censored> -Outfile test.txt
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation : (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException
    + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

Error HTTP 429
Invoke-WebRequest : The remote server returned an error : (429) Too Many Requests.
At line:1 char:1
+ Invoke-WebRequest -Uri "https://<censored> -Outfile test.txt
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation : (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException
    + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

score 2 · Accepted Answer · answered Oct 09 '19 at 10:17

You can do something like this:

try 
{
    $response = Invoke-WebRequest -Uri $download_url -OutFile $srr_file
} 
catch 
{
    switch ($_.Exception.Response.StatusCode.Value__)
    {
        404 { 
            // Here´s the code I would like to write if the HTTP response is 404 File not found
            // Will certainly be a continue command            
            }
        429 {
            // Here´s the code I would like to write if the HTTP response is 429 Too many request
            // Will certainly be a sleep command for 1 hour 
            }
    }
}

Since it's the same exception being thrown, you wont be able to catch them separately.

How to differentiate Invoke-WebRequest exception (HTTP error code) in try catch statement

1 Answers1