Public/Invoke-Download.ps1
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<#
.SYNOPSIS Downloads a file from a specified URI. .DESCRIPTION The Invoke-Download function downloads a file from a specified URI and saves it to the specified destination. .PARAMETER Uri The URI of the file to download. URL is accepted as an alias. .PARAMETER Destination The destination folder where the downloaded file will be saved. Default is the current working directory. .PARAMETER FileName The name of the downloaded file. If not provided, the function will attempt to extract the filename from the URI. .PARAMETER UserAgent The user agent string to use for the request. By default, it uses two user agent strings: 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36' and 'Googlebot/2.1 (+http://www.google.com/bot.html)'. You can specify multiple user agent strings as an array. .PARAMETER Headers Additional headers to include in the request. Default is @{'accept' = '*/*'}, which is needed to trick some servers into serving a download, such as from FileZilla. .PARAMETER TempPath The temporary folder path to use for storing the downloaded file temporarily. Default is the user's temp folder. .PARAMETER IgnoreDate If specified, the function will not set the last modified date of the downloaded file. .PARAMETER BlockFile If specified, the downloaded file will be marked as downloaded from the internet. .PARAMETER NoClobber If specified, the function will not overwrite an existing file with the same name in the destination folder. .PARAMETER NoProgress If specified, the function will not display a progress bar during the download. .PARAMETER PassThru If specified, the function will return the downloaded file object. .EXAMPLE Invoke-Download -Uri 'https://example.com/file.txt' -Destination 'C:\Downloads' This example downloads the file from the specified URI and saves it to the 'C:\Downloads' folder. #> function Invoke-Download { [CmdletBinding()] param( [Parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $true)] [Alias('Url')] [ValidateNotNullOrEmpty()] [string]$Uri, [Parameter(Position = 1)] [ValidateNotNullOrEmpty()] [string]$Destination = $PWD.Path, [Parameter(Position = 2)] [string]$FileName, [string[]]$UserAgent = @('Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36', 'Googlebot/2.1 (+http://www.google.com/bot.html)'), [hashtable]$Headers = @{accept = '*/*' }, [string]$TempPath = [System.IO.Path]::GetTempPath(), [switch]$IgnoreDate, [switch]$BlockFile, [switch]$NoClobber, [switch]$NoProgress, [switch]$PassThru ) begin { # Required on Windows Powershell only if ($PSEdition -eq 'Desktop') { Add-Type -AssemblyName System.Net.Http Add-Type -AssemblyName System.Web } # Enable TLS 1.2 in addition to whatever is pre-configured [Net.ServicePointManager]::SecurityProtocol = [Net.ServicePointManager]::SecurityProtocol -bor [Net.SecurityProtocolType]::Tls12 # Create one single client object for the pipeline $HttpClient = New-Object System.Net.Http.HttpClient foreach ($Header in $Headers.GetEnumerator()) { $HttpClient.DefaultRequestHeaders.Add($Header.Key, $Header.Value) } } process { $ResolveUriSplat = @{ Uri = $Uri UserAgent = $UserAgent Headers = $Headers } $Properties = Resolve-Uri @ResolveUriSplat -ErrorAction Stop if ([string]::IsNullOrEmpty($FileName)) { if ([string]::IsNullOrEmpty($Properties.FileName)) { Write-Error "No filename found for $Uri" return } else { $FileName = $Properties.FileName } } $DestinationFilePath = Join-Path $Destination $FileName # Exit if -NoClobber specified and file exists. if ($NoClobber -and (Test-Path -LiteralPath $DestinationFilePath -PathType Leaf)) { Write-Error 'NoClobber switch specified and file already exists' return } foreach ($UserAgentString in $UserAgent) { $HttpClient.DefaultRequestHeaders.Remove('User-Agent') | Out-Null if ($UserAgentString) { Write-Verbose "$($MyInvocation.MyCommand): Using UserAgent '$UserAgentString'" $HttpClient.DefaultRequestHeaders.Add('User-Agent', $UserAgentString) } $ResponseStream = $HttpClient.GetStreamAsync($Uri) if ($ResponseStream.Result.CanRead) { break } else { continue } } if (!$ResponseStream.Result.CanRead) { throw "$($MyInvocation.MyCommand): $($ResponseStream.Exception.InnerException.Message)" } # Check TempPath exists and create it if not if (-not (Test-Path -LiteralPath $TempPath -PathType Container)) { Write-Verbose "$($MyInvocation.MyCommand): Temp folder '$TempPath' does not exist" try { New-Item -LiteralPath $Destination -ItemType Directory -Force | Out-Null Write-Verbose "$($MyInvocation.MyCommand): Created temp folder '$TempPath'" } catch { Write-Error "$($MyInvocation.MyCommand): Unable to create temp folder '$TempPath': $_" return } } # Generate temp file name $TempFileName = (New-Guid).ToString('N') + ".tmp" $TempFilePath = Join-Path $TempPath $TempFileName # Check Destination exists and create it if not if (-not (Test-Path -LiteralPath $Destination -PathType Container)) { Write-Verbose "$($MyInvocation.MyCommand): Output folder '$Destination' does not exist" try { New-Item -Path $Destination -ItemType Directory -Force | Out-Null Write-Verbose "$($MyInvocation.MyCommand): Created output folder '$Destination'" } catch { Write-Error "$($MyInvocation.MyCommand): Unable to create output folder '$Destination': $_" return } } # Open file stream try { $FileStream = [System.IO.File]::Create($TempFilePath) } catch { Write-Error "$($MyInvocation.MyCommand): Unable to create file '$TempFilePath': $_" return } if ($FileStream.CanWrite) { Write-Verbose "$($MyInvocation.MyCommand): Downloading to temp file '$TempFilePath'..." $Buffer = New-Object byte[] 64KB $BytesDownloaded = 0 $ProgressIntervalMs = 250 $ProgressTimer = (Get-Date).AddMilliseconds(-$ProgressIntervalMs) while ($true) { try { # Read stream into buffer $ReadBytes = $ResponseStream.Result.Read($Buffer, 0, $Buffer.Length) # Track bytes downloaded and display progress bar if enabled and file size is known $BytesDownloaded += $ReadBytes if (!$NoProgress -and (Get-Date) -gt $ProgressTimer.AddMilliseconds($ProgressIntervalMs)) { if ($Properties.FileSizeBytes) { $PercentComplete = [System.Math]::Floor($BytesDownloaded / $Properties.FileSizeBytes * 100) Write-Progress -Activity "Downloading $FileName" -Status "$BytesDownloaded of $($Properties.FileSizeBytes) bytes ($PercentComplete%)" -PercentComplete $PercentComplete } else { Write-Progress -Activity "Downloading $FileName" -Status "$BytesDownloaded of ? bytes" -PercentComplete 0 } $ProgressTimer = Get-Date } # If end of stream if ($ReadBytes -eq 0) { Write-Progress -Activity "Downloading $FileName" -Completed $FileStream.Close() $FileStream.Dispose() try { Write-Verbose "$($MyInvocation.MyCommand): Moving temp file to destination '$DestinationFilePath'" $DownloadedFile = Move-Item -LiteralPath $TempFilePath -Destination $DestinationFilePath -Force -PassThru } catch { Write-Error "$($MyInvocation.MyCommand): Error moving file from '$TempFilePath' to '$DestinationFilePath': $_" return } if ($IsWindows) { if ($BlockFile) { Write-Verbose "$($MyInvocation.MyCommand): Marking file as downloaded from the internet" Set-Content -LiteralPath $DownloadedFile -Stream 'Zone.Identifier' -Value "[ZoneTransfer]`nZoneId=3" } else { Unblock-File -LiteralPath $DownloadedFile } } if ($Properties.LastModified -and -not $IgnoreDate) { Write-Verbose "$($MyInvocation.MyCommand): Setting Last Modified date" $DownloadedFile.LastWriteTime = $Properties.LastModified } Write-Verbose "$($MyInvocation.MyCommand): Download complete!" if ($PassThru) { $DownloadedFile } break } $FileStream.Write($Buffer, 0, $ReadBytes) } catch { Write-Error "$($MyInvocation.MyCommand): Error downloading file: $_" Write-Progress -Activity "Downloading $FileName" -Completed $FileStream.Close() $FileStream.Dispose() break } } } } end { $HttpClient.Dispose() } } |