Where to insert a script to generate a report from auth.log just before rotating it?

[Adam Funk]

A while back on another list I was advised that auth.log (and syslog
and a few others) are rotated by /etc/cron.weekly/sysklogd.  I'm now
interested in running a Perl program to generate a report from
auth.log just before each rotation.

Should I just insert my report-generating command into that file at
one of the points marked below?

Thanks,
Adam

#! /bin/sh
#[comments snipped]
test -x /usr/sbin/syslogd-listfiles || exit 0
test -x /sbin/syslogd || exit 0
test -f /usr/share/sysklogd/dummy || exit 0

set -e

cd /var/log

# insert the following?   <-------
/path/to/my_report auth.log |mail -s 'auth.log report' root

for LOG in `syslogd-listfiles --weekly`
do
   if [ -s $LOG ]; then

      # or is it safer to do it here?   <-------
      if [ "$LOG" == "auth.log ]; then
	 /path/to/my_report auth.log |mail -s 'auth.log report' root
      fi

      savelog -g adm -m 640 -u root -c 4 $LOG >/dev/null
   fi
done

# Restart syslogd
#
/etc/init.d/sysklogd reload-or-restart > /dev/null