#!/usr/bin/perl

use strict;
use warnings;
use Expect;

my $command = "cat > tmp.txt";
my @params;
my $exp = Expect->spawn($command, @params)
    or die "Cannot spawn $command: $!\n";

print("sending...\n");
$exp->send("Hello world\n");
sleep 1;
$exp->hard_close;

__END__