A small perl-based nanny program I used to keep bind running on my system.

It checks both that a process is running and uses dig to make sure it is
answering queries.  It's definately simple and probably a stop-gap solution.

util/nanny.pl

@@ -0,0 +1,60 @@
+#!/usr/bin/perl
+#
+# Copyright (C) 2000  Internet Software Consortium.
+# 
+# Permission to use, copy, modify, and distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+# 
+# THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+# ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+# CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+# DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+# PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+# SOFTWARE.
+#
+# A simple nanny to make sure named stays running.
+
+$pid_file_location = '/var/run/named.pid';
+$nameserver_location = 'localhost';
+$dig_program = 'dig';
+$named_program =  'named';
+
+fork() && exit();
+
+for (;;) {
+  $pid = 0;
+  open(FILE, $pid_file_location) || goto restart;
+  $pid = <FILE>;
+  close(FILE);
+  chomp($pid);
+  
+  $ps_command = "ps -axw | grep named | grep $pid |";
+  # ps_command MUST end in a pipe (|) character!
+
+  # Make sure there's a named on the pid we just got.  Since there is no
+  # good way to test this, use the output from ps.
+  open(PIPE, $ps_command) || die($ps_command);
+  $line = <PIPE>;
+  close(PIPE);
+  chomp($line);
+
+  goto restart if ($line eq "");
+
+  $dig_command = "$dig_program +short . \@$nameserver_location > /dev/null";
+  $return = system($dig_command);
+  goto restart if ($return == 9);
+
+  sleep 90;
+  next;
+
+ restart:
+  if ($pid != 0) {
+    kill 15, $pid;
+    sleep 30;
+  }
+  system ($named_program);
+  sleep 120;
+}