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#PSTip Access web from PowerShell console

As I am still running PowerShell 2.0 on my work computer, I can’t use the Invoke-WebRequest cmdlet. This cmdlet is introduced in Windows PowerShell 3.0. When I need to download some web page, I still use my old .NET friend–Net.WebClient class.

The following command will download the Bing home page:

(New-Object Net.WebClient).DownloadString(‘http://www.bing.com’

As I use this class frequently, I’ve created a function for that and I am exposing a Net.WebClient object as a variable to my global scope.

function New-WebClient
{
    $wc = New-Object Net.WebClient

    $wc.UseDefaultCredentials = $true
    $wc.Proxy.Credentials = $wc.Credentials

    $wc.Encoding = [System.Text.Encoding]::UTF8
    $wc.CachePolicy = New-Object System.Net.Cache.HttpRequestCachePolicy([System.Net.Cache.HttpRequestCacheLevel]::NoCacheNoStore)

    Write-Output $wc
}

$Global:wc = New-WebClient

As you can see I’ve set also some other properties to satisfy my needs:

  1. Use of default credentials. As we user proxy with authentication, I need to pass my actual credentials to proxy.
  2. Setting encoding to UTF8
  3. I am not using cache.

At the end of New-WebClient function, I send the object out and assign it to a global $wc variable. I can use it later as in the following command:

$web = $wc.DownloadString('http://www.bing.com')

I know that some people uses this technique to process RSS channels. I don’t use it for this scenario, but you can download RSS channel, convert it to XML and then process in console. Frequent usage is:

PS> $rss =  $wc.DownloadString('http://feeds.feedburner.com/PowershellMagazine')
PS> $rss.rss.channel.item | Format-Table Title

title
-----
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Filed in: Columns, Tips and Tricks Tags: , ,

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