Save-Download.ps1

Save-Download.ps1

function Save-Download {
    <#
    .SYNOPSIS
        Given either the result of WebResponseObject or a Uri, will download the file to disk without having to specify a name.
    .DESCRIPTION
        Given either the result of WebResponseObject or a Uri, will download the file to disk without having to specify a name.
    .PARAMETER WebResponse
        A WebResponseObject from running an Invoke-WebRequest on a file to download.
    .PARAMETER Uri
        Uri of a file to download in lieu of supplying a WebResponseObject.
    .PARAMETER Directory
        Directory to save download into. Defaults to the current working directory.
    .EXAMPLE
        # Download Microsoft Edge
        $download = Invoke-WebRequest -Uri "https://go.microsoft.com/fwlink/?linkid=2109047&Channel=Stable&language=en&consent=1"
        $download | Save-Download 
    #>
    [CmdletBinding(DefaultParameterSetName = 'Uri')]
    param (
        
        [Parameter(Mandatory = $true, ValueFromPipeline, ParameterSetName = 'WebResponse')]
        [Microsoft.PowerShell.Commands.WebResponseObject]
        $WebResponse,

        [Parameter(Mandatory = $true, ParameterSetName = 'Uri')]
        [string]
        $Uri,

        [Parameter(Mandatory = $false)]
        [string]
        $Directory = (Get-Location).Path
    )

    If ($PSCmdlet.ParameterSetName -eq 'Uri') {
        
        do {
            $WebResponse = Invoke-WebRequest -Uri $Uri -UserAgent 'Mozilla/5.0' -MaximumRedirection 0 -ErrorAction:SilentlyContinue
                
            If ([bool]$WebResponse.Headers.Location) {
                $Uri = $WebResponse.Headers.Location
                Write-Verbose "Redirected to: $Uri"
            }

        } until (!$WebResponse.Headers.Location)
    }

    $errorMessage = "Cannot determine filename for download."

    if (!($WebResponse.Headers.ContainsKey("Content-Disposition"))) {
        
        If ($Uri) {
            Write-Verbose "No content disposition header, using filename from Uri"
            $fileName = Split-Path -Path $Uri -Leaf
        }
        else {
            $fileName = ''
        }

    }
    else
    {
        $content = [System.Net.Mime.ContentDisposition]::new($WebResponse.Headers["Content-Disposition"])
        $fileName = $content.FileName
    }

    if (!$fileName) {
        Write-Error $errorMessage -ErrorAction Stop
    }

    if (!(Test-Path -Path $Directory)) {
        New-Item -Path $Directory -ItemType Directory
    }
    
    $fullPath = Join-Path -Path $Directory -ChildPath $fileName

    Write-Verbose "Downloading to $fullPath"

    $file = [System.IO.FileStream]::new($fullPath, [System.IO.FileMode]::Create)
    $file.Write($WebResponse.Content, 0, $WebResponse.RawContentLength)
    $file.Close()
}