if else based on output of invoke-webrequest in PS

Question

Can someone help me capture only the StatusCode of invoke-webrequest below so that I can determine if a site is up (200) or down (any other code). I think essentially an if

Answer 1

This might work

$uri = $args[0]

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

try{
    if((Invoke-WebRequest $uri -UseBasicParsing -DisableKeepAlive -Method Head).StatusCode -eq 200)
    {
        Write-Output "The site is up."
    }
}
catch {
    Write-Output "The site is down."
}

Answer 2

There are more status codes that can be returned. See HTTP Status Codes.

So maybe a bit more fine-grained script would be a better choice?

$uri = $args[0]
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

try{
    $status = [int](Invoke-WebRequest $uri -UseBasicParsing -DisableKeepAlive -Method Head).StatusCode
    switch ($status) {
        {$_ -ge 100 -and $_ -lt 200}  { Write-Output "The site is up. Statuscode: $status"; break }
        {$_ -ge 200 -and $_ -lt 300}  { Write-Output "The site is up. Statuscode: $status"; break }
        {$_ -ge 300 -and $_ -lt 400}  { Write-Output "The site is redirected. Statuscode: $status"; break }
        {$_ -ge 400 -and $_ -lt 500}  { Write-Output "Client error. Statuscode: $status"; break }
        {$_ -ge 500 -and $_ -lt 600}  { Write-Output "Server error. Statuscode: $status"; break }
        default { Write-Output "The site returned an unhandled status code. Statuscode: $status"}
    }
}
catch {
    Write-Error "An error occurred on Invoke-WebRequest.`r`n$($_.Exception.Message)"
}

Instead of the Invoke-WebRequest you could also use [System.Net.WebRequest]. Something like:

$uri = $args[0]
[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

try{
    # Web request
    $res = ([System.Net.WebRequest]::Create($uri)).GetResponse()
}
catch {
    $res = $_.Exception.Response
}
$status = [int]$res.StatusCode
switch ($status) {
    {$_ -ge 100 -and $_ -lt 200}  { Write-Output "The site is up. Statuscode: $status"; break }
    {$_ -ge 200 -and $_ -lt 300}  { Write-Output "The site is up. Statuscode: $status"; break }
    {$_ -ge 300 -and $_ -lt 400}  { Write-Output "The site is redirected. Statuscode: $status"; break }
    {$_ -ge 400 -and $_ -lt 500}  { Write-Output "Client error. Statuscode: $status"; break }
    {$_ -ge 500 -and $_ -lt 600}  { Write-Output "Server error. Statuscode: $status"; break }
    default { Write-Output "An unhandled error occurred. Statuscode: $status"}
}
# Dispose response if available
if($res){ $res.Dispose() }

Answer 3

Use property dereferencesmember access operator and if to do the work.

$uri = $args[0]

[Net.ServicePointManager]::SecurityProtocol = ([Net.SecurityProtocolType]::Tls12, [Net.SecurityProtocolType]::Tls11, [Net.SecurityProtocolType]::Tls, [Net.SecurityProtocolType]::Ssl3)

try {
    if ((Invoke-WebRequest $uri -UseBasicParsing -DisableKeepAlive -Method Head).StatusCode -eq 200) {
        Write-Host "The site is up."
    }
    else {
        Write-Host "The site is down."
    }
}
catch {
    Write-Host "The site is down."
}

The script above has been modified, some comments below are obsolete.