Perl

Detect End-of-File on a Remote SFTP File

Demonstrates the Chilkat SFtp.Eof method, which returns whether the most recent read for a handle received the SFTP end-of-file status. The only argument is the handle. This example reads until Eof is true.

Background: The timing here is worth understanding: reading exactly through the final byte does not immediately set EOF. The next read succeeds, returns zero bytes, sets the status to SSH_FX_EOF, and only then does Eof report true. That is why the loop tests Eof after each read rather than assuming a short read means the end — a short read can also just be the server returning less than requested.

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Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates the SFtp.Eof method, which returns whether the most recent read for a handle
# received the SFTP end-of-file status.  The only argument is the handle.

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

# Connect, authenticate, and initialize the SFTP subsystem.
my $port = 22;
my $success = $sftp->Connect('sftp.example.com', $port);
if (!$success) {
    print $sftp->LastErrorText, "\n";
    exit;
}

# 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.
my $password = 'mySshPassword';

$success = $sftp->AuthenticatePw('mySshLogin', $password);
if (!$success) {
    print $sftp->LastErrorText, "\n";
    exit;
}

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

my $handle = $sftp->OpenFile('subdir/data.txt', 'readOnly', 'openExisting');
if (!$sftp->LastMethodSuccess) {
    print $sftp->LastErrorText, "\n";
    exit;
}

# Read until Eof reports the end of the file.  Note that reading exactly through the final byte
# does not set EOF; the next read returns zero bytes and then Eof becomes true.
my $sbContent = Chilkat2::StringBuilder->new;
my $chunkSize = 4096;
my $reading = 1;
while ($reading) {
    my $chunk = $sftp->ReadFileText($handle, $chunkSize, 'utf-8');
    if ($sftp->LastReadFailed($handle)) {
        print $sftp->LastErrorText, "\n";
        exit;
    }

    $sbContent->Append($chunk);
    $reading = !$sftp->Eof($handle);
}

$success = $sftp->CloseHandle($handle);
if (!$success) {
    print $sftp->LastErrorText, "\n";
    exit;
}

print $sbContent->GetAsString(), "\n";

$sftp->Disconnect();