Perl

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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

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

my $sftp = Chilkat2::SFtp->new;

# Set some timeouts, in milliseconds:
$sftp->ConnectTimeoutMs(5000);
$sftp->IdleTimeoutMs(10000);

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

# After authenticating, the SFTP subsystem must be initialized:
$success = $sftp->InitializeSftp();
if (!$success) {
    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.)
my $handle = $sftp->OpenFile('big.zip', 'writeOnly', 'createTruncate');
if (!$sftp->LastMethodSuccess) {
    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.
my $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.
my $fac = Chilkat2::FileAccess->new;

$success = $fac->OpenForRead($localFilePath);
if (!$success) {
    $sftp->CloseHandle($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?
my $blockSize = 131072;
my $numBlocks = $fac->GetNumBlocks($blockSize);
print 'Number of blocks = ', $numBlocks, "\n";

my $bd = Chilkat2::BinData->new;
my $i = 0;
while ($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) {
        $sftp->CloseHandle($handle);
        print $fac->LastErrorText, "\n";
        exit;
    }

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

print "Success.\n";