use Net::SSH qw(sshopen3);
use strict;
use warnings;

# Watch for children and reap them.  This is to avoid zombies left by the ssh.
$SIG{CHLD} = 'IGNORE';

my $command = "/usr/bin/date";
foreach $system (@system_list){
   sshopen3( $system, *WRITER, *READER, *ERROR, $command ) || die "ssh: $!";
   while (<READER>) {
      chomp();
      $date{$system} = $_;
      # Or do other stuff
   }
   close(READER);
   close(WRITER);
   close(ERROR);
}