PHP Extension

SFTP Upload Large File in Parts

See more SFTP Examples

Demonstrates how to split a large file into N parts and then upload each part separately. This technique can be used to potentially avoid limits a SFTP server might impose on upload file size. PHP Extension

<?php

include("chilkat.php");

$success = false;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$sftp = new CkSFtp();

// Set some timeouts, in milliseconds:
$sftp->put_ConnectTimeoutMs(5000);
$sftp->put_IdleTimeoutMs(10000);

// Connect to the SSH server.  
// The standard SSH port = 22
// The hostname may be a hostname or IP address.
$hostname = 'sftp.example.com';
$port = 22;
$success = $sftp->Connect($hostname,$port);
if ($success != true) {
    print $sftp->lastErrorText() . "\n";
    exit;
}

// Authenticate with the SSH server.  Chilkat SFTP supports
// both password-based authenication as well as public-key
// authentication.  This example uses password authenication.
$success = $sftp->AuthenticatePw('myLogin','myPassword');
if ($success != true) {
    print $sftp->lastErrorText() . "\n";
    exit;
}

// After authenticating, the SFTP subsystem must be initialized:
$success = $sftp->InitializeSftp();
if ($success != true) {
    print $sftp->lastErrorText() . "\n";
    exit;
}

// Open a remote file for writing on the SSH server.
// If the file already exists, it is overwritten.
// (Specify "createNew" instead of "createTruncate" to
// prevent overwriting existing files.)
$handle = $sftp->openFile('big.zip','writeOnly','createTruncate');
if ($sftp->get_LastMethodSuccess() != true) {
    print $sftp->lastErrorText() . "\n";
    exit;
}

// We're going to upload the local file "qa_data/zips/big.zip" (a relative local path from our current working directory)
// to the SFTP server.
$localFilePath = 'qa_data/zips/big.zip';

// Rather than uploading in one shot, we'll read the local file in chunks
// and upload a chunk at a time.
$fac = new CkFileAccess();

$success = $fac->OpenForRead($localFilePath);
if ($success == false) {
    $sftp->CloseHandle($handle);
    print $fac->lastErrorText() . "\n";
    exit;
}

// If we were to split the local file into 128K chunks, how many chunks (blocks) would
// we have, including the last partial block?
$blockSize = 131072;
$numBlocks = $fac->GetNumBlocks($blockSize);
print 'Number of blocks = ' . $numBlocks . "\n";

$bd = new CkBinData();
$i = 0;
while ($i < $numBlocks) {
    // Read the Nth block, which gets appended to the bd.  (which means
    // we must clear the contents of bd before the next iteration)
    $success = $fac->ReadBlockBd($i,$blockSize,$bd);
    if ($success == false) {
        $sftp->CloseHandle($handle);
        print $fac->lastErrorText() . "\n";
        exit;
    }

    // Upload this block to the open remote file.
    $success = $sftp->WriteFileBd($handle,$bd);
    if ($success == false) {
        print $sftp->lastErrorText() . "\n";
        exit;
    }

    // Clear the contents for the next iteration.
    $bd->Clear();

    $i = $i + 1;
}

// Close the local file.
$fac->FileClose();

// -----------------------------------------------------------------------------
// This is important.  You must close the handle on the server.
// Otherwise open handles will accumulate on the server until eventually a limit
// is reached and the server will fail on a call to OpenFile.
// -----------------------------------------------------------------------------

// Close the remote file handle on the server.
$success = $sftp->CloseHandle($handle);
if ($success != true) {
    print $sftp->lastErrorText() . "\n";
    exit;
}

print 'Success.' . "\n";

?>