One optimisation you could do, is just doing one ps and searching for your processes in the output of that one. (Although you prefer not to use modules, have a look at Proc::ProcessTable for this). Some code that does this without modules:

use strict;
my $interesting_process="ftp"; # Adjust to taste
my @processlist=grep(/$interesting_process/,`ps -fe`); #backtics are e
+vil - consider Proc::ProcessTable
[download]

The processlist array now contains those processes that have ftp somewhere in them (you might want to refine this, as it will also match processes by a user called daftpeter, for example). You can then browse through this list, count the processes, or do whatever you have to do to verify that everything that you expect to be running is actually running.

Disclaimer: code is untested.

CU
Robartes-