PHP ftp_nb_get() Function

The PHP ftp_nb_get() function downloads a file from the FTP server, and saves it into a local file (non-blocking).

The difference between this function and ftp_get() is that this function retrieves the file asynchronously, so your program can perform other operations while the file is being downloaded.

Syntax

ftp_nb_get(ftp, local_file, server_file, 
             mode, offset)

Parameters

`ftp`	`Required.` Specify the FTP connection to use.
`local_file`	`Required.` Specify the local file path (will be overwritten if the file already exists).
`server_file`	`Required.` Specify the server file to download.
`mode`	`Optional.` Specify the transfer mode. Must be either FTP_ASCII or FTP_BINARY.
`offset`	`Optional.` Specify the position in the remote file to start downloading from.

Return Value

Returns any of the following values:

FTP_FAILED: Asynchronous transfer has failed.
FTP_FINISHED: Asynchronous transfer has finished.
FTP_MOREDATA: Asynchronous transfer is still active.

Example:

The example below shows the usage of ftp_nb_get() function.

<?php
//FTP server to use
$ftp_server = "ftp.example.com";

//username for the FTP Connection
$ftp_user = "user";
  
//password for the user
$ftp_pass = "password";
   
//set up a connection or die 
$ftp = ftp_connect($ftp_server)
    or die("Could not connect to $ftp_server");
   
if($ftp) {
  echo "Successfully connected to $ftp_server!\n";
 
  if(@ftp_login($ftp, $ftp_user, $ftp_pass)) {
    echo "Connected as $ftp_user@$ftp_server\n";

    //local file path where 
    //the file to be downloaded
    $local_file = "local_demo.txt";
      
    //server file path which 
    //need to be downloaded
    $server_file = "server_demo.txt";
      
    //downloading the specified server file
    $ret = ftp_nb_get($ftp, $local_file, 
                    $server_file, FTP_ASCII);

    while ($ret == FTP_MOREDATA) {
      //continue downloading...
      $ret = ftp_nb_continue($ftp);
    }

    if ($ret == FTP_FINISHED) {
      echo "Successfully downloaded $server_file\n";
    } else {
      echo "Error while downloading $server_file\n";
      exit(1);
    }
    
  } else {
    echo "Couldn't connect as $ftp_user\n";
  }
 
  //close the connection
  if(ftp_close($ftp)) {
    echo "Connection closed successfully!\n"; 
  } 
}
?>

The output of the above code will be:

Successfully connected to ftp.example.com!
Connected as user@ftp.example.com
Successfully downloaded server_demo.txt
Connection closed successfully!

❮ PHP FTP Reference