Can't get SFTP to work in PHP

Question

I am writing a simple SFTP client in PHP because we have the need to programatically retrieve files via n remote servers. I am using the PECL SSH2 extension.

I have run up against a road block, though. The documentation on php.net suggests that you can do this:

$stream = fopen("ssh2.sftp://$sftp/path/to/file", 'r');

However, I have an ls method that attempts to something similar

public function ls($dir)
{
    $rd = "ssh2.sftp://{$this->sftp}/$dir";
    $handle = opendir($rd);
    if (!is_resource($handle)) {
        throw new SFTPException("Could not open directory.");
    }

    while (false !== ($file = readdir($handle))) {
        if (substr($file, 0, 1) != '.'){
            print $file . "\n";
        }
    }
    closedir($handle);
}

I get the following error:

PHP Warning:  opendir(): Unable to open ssh2.sftp://Resource id #5/outgoing on remote host

This makes perfect sense because that's what happens when you cast a resource to string. Is the documentation wrong? I tried replacing the resource with host, username, and host and that didn't work either. I know the path is correct because I can run SFTP from the command line and it works fine.

Has anyone else tried to use the SSH2 extenstion with SFTP? Am I missing something obvious here?

UPDATE:

I setup sftp on another machine in-house and it works just fine. So, there must be something about the server I am trying to connect to that isn't working.

Answer 1

When connecting to a SFTP server and you need to connect to the root folder (for instance for reading the content of the folder) you would still get the error when using just "/" as the path.

The solution that I found was to use the path "/./", that's a valid path that references to the root folder. This is useful when the user you are logging with has access only to its own root folder and no full path is available.

So the request to the server when trying to read the contents of the root folder should be something like this:

$rd = "ssh2.sftp://{$this->sftp}/./";