Another quasi ugly system call could be something like

use strict;

my($ps_cmd,$found);

$ps_cmd = '/bin/ps -auwx';

open(IN,"$ps_cmd|") || die "Couldnt exec $ps_cmd\nReason: $!\n";

while ( <IN> ) {
   ($found++ && last) if ($_ =~ /inetd/);
}

print STDERR "Danger Will Robinson\n" if (!$found);
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Also below there was a post about collecting the ps output into an array, and then grep()'ing inetd from the output, which works nicely too...
P.S. Code tested clean on FreeBSD