Powershell query to download file from web

Question

Hi

My powershell query downloads a file with 0 kb. That isn't right. Copying and pasting the $Source URL in a browser will let me download the file. That file is correct. However for some reason when I use the Start-BitsTransfer cmdlet the rates.csv file gets created but it has no data in it. What am I doing wrong?

$Source = "https://home.treasury.gov/resource-center/data-chart-center/interest-rates/daily-treasury-rates.csv/all/all?type=daily_treasury_yield_curve&field_tdr_date_value=all&page&_format=csv"  
$Destination = "C:\Users\Me\Documents\Discount_Rates\rates.csv"  
Start-BitsTransfer $Source $Destination  

@Rich Matheisen , are you able to help?

Thank you

Answer 1

Hi @Manny ,

why not using Invoke-WebRequest instead of Start-BitsTransfer ?

This works here:

$Source = "https://home.treasury.gov/resource-center/data-chart-center/interest-rates/daily-treasury-rates.csv/all/all?type=daily_treasury_yield_curve&field_tdr_date_value=all&page&_format=csv"  
$Destination = ".\Junk\rates.csv"  
Invoke-WebRequest -Uri $source -OutFile $Destination  

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(If the reply was helpful please don't forget to upvote and/or accept as answer, thank you)

Regards
Andreas Baumgarten

Answer 2

I had a look at the Start-BitsTransfer (using your source) with both Fiddler and WireShark. I can see the TLS handshake and then . . . nothing. :-/

I used this code to download the file, though:

$WebClient = New-Object System.Net.WebClient
$WebClient.DownloadFile($source,$destination)

It's faster than Invoke-WebRequest and, because it doesn't try to parse the HTML in the response, less prone to hanging.

Answer 3

It's always best to stick with the datetime object to handle the conversion of dates and times. The results are consistent and the datetime object store the information that makes it possible to do comparisons and date arithmetic.

# BEST - parses date according to string and produces a datetime object
[datetime]::ParseExact("3/05/2022","M/d/yyyy",$null)

# works, but you're still left with a string instead of DateTime object and doesn't always produce 2-character month and day
"03/05/2020" -replace "(\d\d?)/(\d\d?)/(\d\d\d\d)",'$3/$1/$2'

# works but uses indexing and type conversion but output format is consistent
$x = "3/5/2020" -split "/"
"{0:d4}/{1:d2}/{2:d2}" -f [int]$x[2],[int]$x[0],[int]$x[1]

# example of use (pick your poison from the three methods above)
Import-CSV c:\junk\$Destination |
    ForEach-Object{
        $_.Date = [datetime]::ParseExact($_.Date, "M/d/yyyy", $null)    # preferred method
        $_
    } | Export-Csv c:\junk\newfile.csv -NoTypeInformation