I am trying to download files using PowerShell where target file name is not known?

Question

I'm using following script to download files using powershell.

 $folder = "c:\temp\"
$userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 
Firefox/7.0.1"
$web = New-Object System.Net.WebClient
$web.Headers.Add("user-agent", $userAgent)


Get-Content "c:\temp\URL_List.txt" |
Foreach-Object { 
"Downloading " + $_
try {
    $target = join-path $folder ([io.path]::getfilename($_))
    $web.DownloadFile($_, $target)
} catch {
    $_.Exception.Message
}

}

The URL_List.txt file has list of URL's I'm trying to download files from. Here's a sample URL from the list: https://drive.google.com/uc?export=download&id=0B84LPHCa2YmdZmFMV0dsYl9FeTg If you look at the URL there's no absolute file name in the URL so I'm not sure how to set the target parameter for WebClient.DownloadFile() method.

Do you have any way to derive the filename after it's downloaded? You can use `[System.IO.Path]::GetTempFileName()` to generate a tmp file to write the request into until you can figure out its name. Also, what version of PowerShell? You should utilize `Invoke-WebRequest -OutFile` instead of manual .net manipulation (as a best-practice) — Maximilian Burszley, Jun 15 '18 at 16:57

score 0 · Answer 1 · answered Jun 18 '18 at 02:23

0

Read the Download Files. Also might be worth checking since you're using Powershell, Google Drive REST Api module for Powershell.

answered Jun 18 '18 at 02:23

Adi Mabfalin

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Mark Berry · Answer 2 · 2019-06-04T14:18:25.130

So the question as I understand it is how to extract the filename for a Google Drive file without downloading the file first

This Chilkat page gave me the idea that it should be possible to access properties with a GET request. Chilkat is a paid API, so I thought I'd try to cobble together a method using direct PowerShell commands.

Invoke-WebRequest works but downloads the whole file. We only need the headers.

This site has the core code for that. From there, it's just parsing the Content-Disposition header to extract the "filename" (and not "filename*"):

$WebPath = "https://drive.google.com/uc?export=download&id=0B84LPHCa2YmdZmFMV0dsYl9FeTg"
$request = [System.Net.WebRequest]::Create( $WebPath ) 
$headers = $request.GetResponse().Headers 
# Content-disposition includes a name-value pair for filename:
$cd = $headers.GetValues("Content-Disposition")
$cd_array = $cd.split(";")
foreach ($item in $cd_array) { 
  if ($item.StartsWith("filename=")) {
      # Get string after equal sign
      $filename = $item.Substring($item.IndexOf("=")+1)
      # Remove quotation marks, if any
      $filename = $filename.Replace('"','')
  }
}

I am trying to download files using PowerShell where target file name is not known?

2 Answers2