my @pslist = ();
while (!@pslist) {
	local $SIG{ALRM} = { die "TIMEOUT" };
	my $pid;
	eval {
		alarm 5; # arrange for a wake-up call in 5 seconds
		
		$pid = open(PSLIST, " ssh -2 $user\@ $peer ./pslist | ")
			|| die "Remote process list gathering error:\n$!.\n";

		while(<PSLIST>){
			chomp($_);
			push(@pslist, $_);
		}
		close(PSLIST);
		
		alarm 0; # clear the alarm, if we got this far ok
	}
	if ($@ =~ /TIMEOUT/) {
		# abort the attempt, and try again
		kill 'TERM' => $pid;
		@pslist = ();
	}
	elsif ($@) {
		die $@;
	}
}

foreach (@service){
	# .. check the existence of a process
}