Perl

Create a Hard Link on an SFTP Server

Demonstrates the Chilkat SFtp.HardLink method, which creates a hard link to an existing remote file. The first argument is the existing file and the second is the new link path. It uses the OpenSSH hardlink@openssh.com extension and succeeds only when the server supports it.

Background: A hard link is a second name for the same file data, not a pointer to a path: both names are equal, the data persists until the last name is removed, and there is no "original" to break. Unlike a symbolic link it cannot span filesystems and cannot target a directory. Because it depends on a non-standard OpenSSH extension, expect it to fail against servers that do not implement it.

Chilkat Perl Downloads

Download Chilkat for Perl

Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates the SFtp.HardLink method, which creates a hard link to an existing remote file.
# The 1st argument is the existing file and the 2nd is the new link path.

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;
}

# Create a hard link.  This uses the OpenSSH hardlink@openssh.com extension and succeeds only
# when the server supports it.
$success = $sftp->HardLink('subdir/data.bin', 'subdir/data_backup.bin');
if (!$success) {
    print $sftp->LastErrorText, "\n";
    exit;
}

print "Hard link created.\n";

$sftp->Disconnect();