Perl

Pre-Allocate Server Space Before an FTP Upload (ALLO)

Demonstrates the AllocateSize property, which sends the FTP ALLO command to pre-allocate disk space on the server before an upload. Set it to the size in bytes of the file about to be uploaded.

Background: ALLO asks the server to reserve storage in advance, a requirement of certain legacy systems — older mainframes in particular — that need the exact file size up front to allocate a dataset. Modern servers allocate space dynamically and typically ignore or accept ALLO without needing it, so most applications never set this. Provide it only when targeting a host known to require pre-allocation.

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use strict;
use warnings;
use Chilkat2;

my $ftp = Chilkat2::Ftp2->new;

$ftp->Hostname('ftp.example.com');
$ftp->Username('myFtpLogin');

# Normally you would not hard-code the password in source.  You should instead obtain it
# from an interactive prompt, environment variable, or a secrets vault.
$ftp->Password('myPassword');

my $success = $ftp->Connect();
if (!$success) {
    print $ftp->LastErrorText, "\n";
    exit;
}

# AllocateSize sends the FTP ALLO command to pre-allocate disk space on the server before an
# upload.  It is rarely needed -- mainly for certain legacy systems that require the exact size
# in advance -- since most servers allocate space dynamically.  Set it to the size in bytes of
# the file about to be uploaded.
ERROR: Assignment type mismatch.  ExpressionType=int, atgType=uint

$success = $ftp->PutFile('qa_data/bigfile.zip', 'uploads/bigfile.zip');
if (!$success) {
    print $ftp->LastErrorText, "\n";
    exit;
}

print "Uploaded with pre-allocation.\n";

$success = $ftp->Disconnect();
if (!$success) {
    print $ftp->LastErrorText, "\n";
    exit;
}