#!/usr/bin/ksh
#
# Cleanup logfiles (daily)
#
# Usage:
#
#   dailylogs.sh   [ DEBUG | TRACE ]
#
# where adding the word DEBUG (all caps) will
#   confirm the logfile operations to stdout
#   by showing each logfile's changes.
#
#   The word TRACE will turn on shell tracing
#   in all modules.
#
set -u

MYNAME=$(basename $0)
DEBUG=0
TRACE=0
if [ $# -gt 0 ]
then
   case $1 in
    TRACE)
        set -x
        TRACE=1
        ;;
    DEBUG) 
        DEBUG=1 
        ;; 
   esac
fi

#####################################################
function TrimLogFile
{
if [ $TRACE -eq 1 ]
then
   set -x
fi

## Send over the full pathname of a logfile as MYLOGFILE
##    Creates $MYARCHIVES archives and zeros the original file
##    Does not rename the existing logfile since it is most likely
##    open.
##
## Example:  MYLOGFILE=/var/adm/syslog/syslog.log
##           MYARCHIVES=5
##           MYCHMOD=644
##           MYCHOWN=root:sys
## Produces:
##           /var/adm/syslog/syslog.log.5.Z
##           /var/adm/syslog/syslog.log.4.Z
##           /var/adm/syslog/syslog.log.3.Z
##           /var/adm/syslog/syslog.log.2.Z
##           /var/adm/syslog/syslog.log.1.Z
##           /var/adm/syslog/syslog.log     (zero length)
##
## If DEBUG=1 then report on the transactions

MYDIR=$(dirname $MYLOGFILE)
MYLOG=$(basename $MYLOGFILE)

# Go through the logs backwards starting with the oldest copy
# (defined by $MYARCHIVES)

NEXTLOG=$MYARCHIVES
while [ $NEXTLOG -gt 1 ]
do
   PREVLOG=$(( NEXTLOG - 1 ))

# If the previous log exists (logs 1 through $MYARCHIVES-1) then
# remove the $NEXTLOG so as to preserve the date/time/permissions
# of the previous file.  If the previous log does not exist, create
# a zero length file and set permissions per $MYCHMOD and $MYCHOWN.

   if [ -f $MYDIR/$MYLOG.$PREVLOG.Z ]
   then
      rm -f $MYDIR/$MYLOG.$NEXTLOG.Z
      cp -pf $MYDIR/$MYLOG.$PREVLOG.Z $MYDIR/$MYLOG.$NEXTLOG.Z 2>&1 > /dev/null
      chmod $MYCHMOD $MYDIR/$MYLOG.$NEXTLOG.Z
      chown $MYCHOWN $MYDIR/$MYLOG.$NEXTLOG.Z
   else
      touch $MYDIR/$MYLOG.$PREVLOG.Z
      chmod $MYCHMOD $MYDIR/$MYLOG.$PREVLOG.Z
      chown $MYCHOWN $MYDIR/$MYLOG.$PREVLOG.Z
   fi
   NEXTLOG=$(( $NEXTLOG - 1 ))
done

# Now take care of the current logfile

rm -f $MYDIR/$MYLOG.1
cp -pf $MYLOGFILE $MYDIR/$MYLOG.1
cat /dev/null > $MYLOGFILE
compress -f $MYDIR/$MYLOG.1
chmod $MYCHMOD $MYDIR/$MYLOG.1.Z
chown $MYCHOWN $MYDIR/$MYLOG.1.Z

if [ $DEBUG -eq 1 -o $TRACE -eq 1 ]
then
   echo "Archive $MYARCHIVES copies and zero $MYLOGFILE:"
   ll $MYLOGFILE
   if [ -f $MYLOGFILE.*.Z ]
   then
      ll $MYLOGFILE*.Z
   fi
fi
}

##################
##              ##
## MAIN PROGRAM ##
##              ##
##################



## cleanup /var/adm/wtmp and /var/adm/btmp..rather than play
## with fwtmp and trying to get a properly formatted file
## with start record, etc, just zero the file and save the
## last ones (test if btmp exists)


   MYARCHIVES=5
   MYCHOWN=adm:adm
   MYCHMOD=664
   MYLOGFILE=/var/adm/wtmp
   TrimLogFile
   MYLOGFILE=/var/adm/btmp
   MYCHOWN=adm:adm
   MYCHMOD=600
   if [ -f $MYLOGFILE ]
   then
      TrimLogFile
   fi
  
##  cleanup cron log

   MYARCHIVES=5
   MYLOGFILE=/usr/lib/cron/log
   MYCHOWN=root:root
   MYCHMOD=644
   TrimLogFile

#  syslog
#
# Send HUP to syslogd to force it to start using the newly zeroed log
# and also record when the new log was started. 

   MYARCHIVES=7
   MYLOGFILE=/var/adm/syslog/syslog.log
   MYCHOWN=root:sys
   MYCHMOD=644
   TrimLogFile
   kill -HUP $(cat /etc/syslog.pid)

#  Trim mail log.  Stop sendmail just 'cause it's a good idea once a day
#  and restart after triming. 


   MYARCHIVES=7
   MYLOGFILE=/var/adm/syslog/mail.log
   MYCHOWN=root:sys
   MYCHMOD=644
   /sbin/init.d/sendmail stop > /dev/null
   TrimLogFile
   newaliases > /dev/null
   /sbin/init.d/sendmail start > /dev/null