Stream FTP download to output

Found a solution!

Create a socket pair (anonymous pipe?). Use the non-blocking ftp_nb_fget function to write to one end of the pipe, and echo the other end of the pipe.

Tested to be fast (easily 10MB/s on a 100Mbps connection) so there's not much I/O overhead.

Be sure to clear any output buffers. Frameworks commonly buffer your output.

public function echo_contents() {
    /* FTP writes to [0].  Data passed through from [1]. */
    $sockets = stream_socket_pair(STREAM_PF_UNIX, STREAM_SOCK_STREAM, STREAM_IPPROTO_IP);

    if($sockets === FALSE) {
        throw new Exception('Unable to create socket pair');
    }

    stream_set_write_buffer($sockets[0], 0);
    stream_set_timeout($sockets[1], 0);

    try {
        // $this->ftp is an FtpConnection
        $get = $this->ftp->get_non_blocking($this->path, $sockets[0]);

        while(!$get->is_finished()) {
            $contents = stream_get_contents($sockets[1]);

            if($contents !== false) {
                echo $contents;
                flush();
            }

            $get->resume();
        }

        $contents = stream_get_contents($sockets[1]);

        if($contents !== false) {
            echo $contents;
            flush();
        }
    } catch(Exception $e) {
        fclose($sockets[0]);    // wtb finally
        fclose($sockets[1]);

        throw $e;
    }

    fclose($sockets[0]);
    fclose($sockets[1]);
}

// class FtpConnection
public function get_non_blocking($path, $stream) {
    // $this->ftp is the FTP resource returned by ftp_connect
    return new FtpNonBlockingRequest($this->ftp, $path, $stream);
}

/* TODO Error handling. */
class FtpNonBlockingRequest {
    protected $ftp = NULL;
    protected $status = NULL;

    public function __construct($ftp, $path, $stream) {
        $this->ftp = $ftp;

        $this->status = ftp_nb_fget($this->ftp, $stream, $path, FTP_BINARY);
    }

    public function is_finished() {
        return $this->status !== FTP_MOREDATA;
    }

    public function resume() {
        if($this->is_finished()) {
            throw BadMethodCallException('Cannot continue download; already finished');
        }

        $this->status = ftp_nb_continue($this->ftp);
    }
}

Try to save it locally first and then push it back to browser.

Use that code to save your file locally.

<?php
                // define some variables
        $folder_path = "YOUR FOLDER PATH";
        $local_file = "LOCAL FILE PATH";
        $server_file = "SERVER FILE PATH";

        //-- Connection Settings
        $ftp_server = "IP ADDRESS"; // Address of FTP server.
        $ftp_user_name = "USERNAME"; // Username
        $ftp_user_pass = "PASSWORD"; // Password
        #$destination_file = "FILEPATH";

        // set up basic connection
        $conn_id = ftp_connect($ftp_server);

        // login with username and password
        $login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);

        // try to download $server_file and save to $local_file
        if (ftp_get($conn_id, $local_file, $server_file, FTP_BINARY)) {
            echo "Successfully written to $local_filen";
        } else {
            echo "There was a problemn";
        }

        // close the connection
        ftp_close($conn_id);
?>

I also found this, maybe it could help you

My FTP-Server always responded "bool(false)" instead of presenting me a directory-listing. I had to add ftp_pasv($conn_id, true); right after the $login_result = ftp_login(...); line. After that it just worked fine.

<?php

// function
function ftp_mksubdirs($ftpcon,$ftpbasedir,$ftpath){
   @ftp_chdir($ftpcon, $ftpbasedir); // /var/www/uploads
   $parts = array_filter(explode('/',$ftpath)); // 2013/06/11/username
   foreach($parts as $part){
      if(!@ftp_chdir($ftpcon, $part)){
         ftp_mkdir($ftpcon, $part);
         //ftp_chmod($ftpcon, 0775, $part);
         ftp_chdir($ftpcon, $part);
      }
   }
}

// usage
$path_of_storage = '/var/www/uploads';
$newftpdir = '2013/06/11/username';

$conn_id = ftp_connect($ftpserver);
ftp_login($conn_id, $login, $pass);
ftp_mksubdirs($conn_id,$path_of_storage,$newftpdir);
ftp_close($conn_id);

?>