#!/usr/bin/perl

use strict;
use warnings;

use Time::HiRes qw(time);
use Net::OpenSSH;
use Error;

my $start = time;
my $ssh = Net::OpenSSH->new($host, user => $user,
                            master_opts => [-i => $key_file]);

warn time - $start . ": connected!\n";
my $timeout = 0.250;
my $output = '';
my $ofh = $ssh->pipe_out('(for i in $(seq 1 10); do sleep 1 && echo line number $i ; done)');
my $fn = fileno $ofh;

while (1) {
  my $rb = '';
  vec($rb, $fn, 1) = 1;
  if (select($rb, undef, undef, $timeout) > 0) {
    my $bytes = sysread($ofh, $output, 1024, length $output);
    last if (!$bytes and (defined $bytes or $! != Error::EINTR()));
    warn time - $start . ": $bytes bytes read\n";
  }
  else {
    warn time - $start . ": timeout!\n";
  }
}
close($ofh);
print "output:\n$output\n";