The following code is intended to simply transfer a file stored on hard disk to a remote sftp server:

sub sftp_transfer {

   my ( $ftp_url, $ftp_user, $ftp_passwd, $ftp_dir, $output_file_path 
+) = @_;

   if ( $debug ) {
   
      print "&sftp_transfer: ";
      print "Host: $ftp_url\n";
      print "User: $ftp_user\n";
      print "Password: $ftp_passwd\n";
      print "Dir: $ftp_dir\n";
      
   }
    
   my %conn = ( "user" => $ftp_user,
                "password" => $ftp_passwd,
                "port" => 2222,
                "autoflush" => 1
              );
              
   my $ftp=Net::SFTP::Foreign->new( $ftp_url, %conn );
   
   if ( $ftp->error ) {
   
      $err_occured = 1;
      $error_msg
         ="SFTP: Cannot connect to sftp-server $ftp_url: " . $ftp->err
+or;
      die ( "\n" )
              
  };
            
   $ftp->setcwd( $ftp_dir )
      or do {
        
            $err_occured = 1;
            $error_msg
             = "SFTP: Cannot cd into $ftp_dir: " . $ftp->error;
            die ( "\n" )
          
        };
   
   my $output_file_name = basename( $output_file_path );
   $ftp->put( $output_file_path, $output_file_name )
       or do {
        
            $err_occured = 1;
            $error_msg
                 = "SFTP: Cannot upload file $output_file_path: " . $f
+tp->error;
            die ( "\n" )
          
        };
        
}
[download]

Output (with $debug == 1)

&sftp_transfer: Host: example.com
User: user
Password: ***
Dir: /POS/21/2100139
Password Authentication
[download]

On the command line, file transfer works flawlessly. When applying the above code, the files transferred have zero Byte size, although not being empty prior to transfer, The sending client is a Linux box, I not know about the server. Any ideas whatis going wrong here?