(PowerShell) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v9.5.0.67 or greater.

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Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

# This requires the Chilkat Zip API to have been previously unlocked.
# See Unlock Chilkat Zip for sample code.

$zip = New-Object Chilkat.Zip

# First open a .zip.
$success = $zip.OpenZip("qa_data/zips/big.zip")
if ($success -ne $true) {
    $($zip.LastErrorText)
    exit
}

# Get the entry to be unzipped to a stream..
$entry = $zip.GetEntryByIndex(0)
if ($zip.LastMethodSuccess -ne $true) {
    $($zip.LastErrorText)
    exit
}

$dataStream = New-Object Chilkat.Stream

$unzipTask = $entry.UnzipToStreamAsync($dataStream)
if ($entry.LastMethodSuccess -ne $true) {
    $($entry.LastErrorText)

    exit
}

# Start the background unzip thread.
$unzipTask.Run()

# We'll read the uncompressed data chunk-by-chunk and write to an output file.
$fac = New-Object Chilkat.FileAccess
$success = $fac.OpenForWrite("qa_output/out.dat")
if ($success -ne $true) {
    $($fac.LastErrorText)

    exit
}

# Read the stream.  (this is reading the unzipped file data)
$bd = New-Object Chilkat.BinData
while ($dataStream.EndOfStream -ne $true) {
    # Get the next chunk of decompressed bytes.
    $dataStream.ReadBd($bd)
    # Do something with it..
    # In this simple example, we'll just write to the file.
    $fac.FileWriteBd($bd,0,0)
    # Clear for the next read.
    $bd.Clear()
}

$fac.FileClose()

$("Success.")