#!/usr/bin/perl
use strict;
use warnings;

use Expect;

my $REMOTE = 'name@server:/dir';
my $LOCAL  = 'file';

my $cmd = "sftp $REMOTE";
my $exp = Expect->spawn($cmd) or die;
$exp->expect(120, "password: ") or die;
$exp->send("dummy\r");
$exp->expect(120, "sftp> ") or die;
$exp->send("put $LOCAL\r");
$exp->expect(600, "sftp> ") or die;
$exp->send("bye\r");
$exp->close();

##</code><code>##

$ perl -v
This is perl, v5.6.1 built for i386-linux
$ perl -MExpect -le 'print $Expect::VERSION'
1.15
$ strings `which sftp` | grep sftp-client
@(#)$OpenBSD: sftp-client.c,v 1.33 2002/06/23 09:30:14 deraadt Exp $