[Expectperl-discuss] Threading on top of IO::Tty seems to work

[Bryan B. <br...@bu...>]

Austin/Roland,

Ok, there have been a few threads lately about threading so I thought i
would re-visit the issue.  I wrote a script that seems to work, but I
would like your opinions on if it really should be working, and/or any
snafu's i may run into if I continue doing it this way.

My script (which I will add to this e-mail) does the following steps in
order:

1. Initialize and store 1 expect object for each host, spawning an SSH
command
2. Get to a command prompt on each expect object, so we have some place to
start
3. Start one thread for each host, sending a list of commands, expecting
the prompt in between each command
4. Close the expect object and return, joining thread

I know it works with at least 5 hosts because i keep separate logs for
each expect session.  I'm using Expect v1.20, IO::Tty v1.07, and i've
tried this on two different hosts:

SunOS 5.10 Generic_125101-09 i86pc
Redhat Linux AS4 2.6.9-5.EL

And finally, here is the script:

--- start --->
#!/usr/bin/perl -w

use strict;
use threads;

use Expect;
$Expect::Log_Stdout = 0;

our $prompt = '[>#\$] $';
my @hosts = ("ravager", "jupiter", "europa", "firebee", "invader");
my %hosts_exp;

foreach my $host (@hosts) {
  print "Getting expect object for $host\n";
  $hosts_exp{$host} = new Expect;

  $hosts_exp{$host}->log_file("$host.log");
  $hosts_exp{$host}->spawn("ssh -x $host");
  $hosts_exp{$host}->expect(5, '-re', $prompt);
}

my $thread_id = 0;
my @thread_ids = ();
my @commands = ("uptime", "who", "who am i", "pwd");
foreach my $host ( keys %hosts_exp ) {
  $thread_ids[$thread_id] = threads->new("run_threaded",
$hosts_exp{$host}, $host, @commands);
  $thread_id++;
}

for (my $t=0; $t<$thread_id; $t++) {
  my $result = $thread_ids[$t]->join();
  if ( ! $result ) { print "Thread $t returned bad result\n"; }
}

sub run_threaded {
  my $exp = shift;
  my $hostname = shift;
  my @commands = @_;

  my $result = 0;
  foreach my $command (@commands) {
    print "Executing on $hostname: $command\n";
    $exp->send("$command \n");
    $result = $exp->expect(5, '-re', $prompt);
    last if ! $result;
  }

  if ($result) {
    $exp->send("exit;\n exit;\n exit;\n");
    $exp->soft_close();
  } else {
    $exp->hard_close();
  }

  return($result);
}
<--- end ---

Thanks,

Bryan Bueter
http://sourceforge.net/projects/rover