Backup in PowerShell

# Set the source and destination paths
$sourcePath = "C:\Path\To\Source\Folder"
$destinationPath = "C:\Path\To\Backup\Folder"

# Create the zip file name with the current date
$zipFileName = "backup_" + (Get-Date -Format "yyyy-MM-dd") + ".zip"

# Set the full destination path including the zip file name
$destinationPath = Join-Path -Path $destinationPath -ChildPath $zipFileName

# Create a new zip archive
$zipFile = [System.IO.Compression.ZipFile]::Open($destinationPath, [System.IO.Compression.ZipArchiveMode]::Create)

# Add the contents of the source folder to the zip archive
[System.IO.Directory]::GetFiles($sourcePath, "*", [System.IO.SearchOption]::AllDirectories) | ForEach-Object {
   $entryName = $_.SubString($sourcePath.Length + 1)
   $zipEntry = $zipFile.CreateEntry($entryName)
   $zipStream = $zipEntry.Open()
   $fileStream = [System.IO.File]::OpenRead($_)
   $fileStream.CopyTo($zipStream)
   $fileStream.Close()
   $zipStream.Close()
}

# Close the zip archive
$zipFile.Dispose()

How it works:

• Set the $sourcePath and $destinationPath variables to the appropriate paths.
• Create the $zipFileName variable by concatenating the string "backup_", the current date formatted as "yyyy-MM-dd", and the file extension ".zip". This will create a zip file with the name "backup_yyyy-MM-dd.zip", e.g. "backup_2023-03-14.zip".
• Use the Join-Path cmdlet to combine the $destinationPath and $zipFileName variables to create the full destination path including the zip file name.
• Create a new zip archive using the [System.IO.Compression.ZipFile]::Open method with the $destinationPath and [System.IO.Compression.ZipArchiveMode]::Create parameters.
• Use the [System.IO.Directory]::GetFiles method to get a list of all the files in the $sourcePath folder and its subdirectories.
• For each file, create an entry in the zip archive using the $zipFile.CreateEntry method with the $entryName variable as the entry name.
• Use the $zipEntry.Open method to open a stream to the zip entry and the [System.IO.File]::OpenRead method to open a stream to the source file.
• Use the $fileStream.CopyTo method to copy the contents of the source file to the zip entry stream.
• Close the source file stream and the zip entry stream using the $fileStream.Close() and $zipStream.Close() methods.
• Close the zip archive using the $zipFile.Dispose() method.