How to access FTP connection from different PHP file? - php

Question

I am trying to create an FTP connection in PHP and trying to access it from other PHP files. Basically my goal is to create an FTP connection and make it available like a session when logging in and then access it from my other PHP files to do other tasks like file upload-download.
My connection class is as follows,
<?php
if($_GET['q'] == 'ftp_connect')
{
$connection = new connect_to_ftp;
echo $connection->ftp_connection();
}
elseif($_GET['q'] == 'get_connection_id')
{
$connection = new connect_to_ftp;
echo $connection->get_connection();
}
class connect_to_ftp
{
public $ftp_server = "";
public $username = "";
public $password = "";
public $connectionID, $login_result, $response;
public function ftp_connection()
{
$this->connectionID = ftp_connect($this->ftp_server);
if($this->connectionID==true)
{
$this->response = array("connection_error" => "Connected to ".$this->ftp_server);
$this->login_result = ftp_login($this->connectionID, $this->username, $this->password);
if($this->login_result==true)
{
$this->response = array("connection_error" => "Login successful to ".$this->ftp_server);
}else
{
$this->response = array("connection_error" => "Failed to login to ".$this->ftp_server." Check username and password");
}
}else
{
$this->response = array("connection_error" => "Could not connect to ".$this->ftp_server);
}
return json_encode($this->response);
}
public function get_connection()
{
return $this->connectionID;
}
}
?>
When I call ftp_connection() using ajax, it successfully connects to the ftp account but later on when I call get_connection() to return me the connection id, it returns me null instead.

Answer 1

Short answer: You can't
Longer answer: file handles, including sockets only exist within the process which opens them (this is not strictly true, it is possible to pass file handles between processes on Linux, but it is very contentious functionality and as with most esoteric things should not be used unless you fully understand the ramifications, and the functionality is not exposed in php).
The options are to either
1) create a connection, carry out the necessary operations then close it within the instance of a php script. Unfortunately FTP is even more badly thought than SMTP but nearly as deeply ingrained. So lots of people have invented built-in security "features" to try to address it's shortcomings. A common one is rate limiting of connections.
2) run an event based daemon to act as the FTP client and connect to that using php. However if you don't understand files and processes then you have a lot of learning to do before you can write such a programming.
Did I mention that FTP sucks? Learn how to use SFTP.