#!/usr/bin/perl
use strict;
use warnings;
use Net::SFTP;

my %args = (
    user     => 'me',
    password => 'xxxxxxxxxx'
); 

my $sftp = Net::SFTP->new( 'ftp.example.com', %args ) || die 'Could not connect to the server: ' . $! . "\n";
$sftp->get( 'file1.txt', 'file1.txt', \&callback ) || die 'Could not fetch remote file: ' . $! . "\n";

sub callback {
    my ( $sftp, $data, $offset, $size ) = @_;
    my $percent = ($offset/$size)*100;
    print $percent . ' ';
    return;
}