PHP

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 PHP Downloads

Download Chilkat for PHP

Chilkat2 PHP

<?php

use Chilkat2\SFtp;

// 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.

$sftp = new SFtp();

// Connect, authenticate, and initialize the SFTP subsystem.
$port = 22;
try {
    $sftp->Connect('sftp.example.com', $port);

    // 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.
    $password = 'mySshPassword';

    $sftp->AuthenticatePw('mySshLogin', $password);

    $sftp->InitializeSftp();

    // Create a hard link.  This uses the OpenSSH hardlink@openssh.com extension and succeeds only
    // when the server supports it.
    $sftp->HardLink('subdir/data.bin', 'subdir/data_backup.bin');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "Hard link created.\n";

$sftp->Disconnect();