#!/bin/ksh
#-----------------------------------------------------------------------------
# $Id: rotatelogs,v 1.1 1999/05/30 00:25:16 peters Exp $
#
# SCRIPT:	rotatelogs
#
# AUTHOR:	Peter Sundstrom (peters@ginini.com.au)
#
# FUNCTION:     Rotate log files and compress old copies by using a central
#		log definition table.
#
# 		Latest version available from 
#		http://www.ginini.com.au/tools/rotatelogs
#
#-----------------------------------------------------------------------------

trap 'echo $0 aborted;exit' 1 2 3 15

USAGE="Usage: `basename $0` [-Dhv] [-f <config file>]"

CONFIG=/usr/local/etc/rotate.conf	# Rotate configuration file
GZIP=/usr/local/bin/gzip		# gzip location
TODAY=`date +%A`                        # Name of Today
DAYOFM=`date +%d`                       # Day of the month

#------------------------------------------------------------------------- 
function help
{
  cat <<EOF
$USAGE

-f      Use specified configuration file.
-h      Display this help.
-v      Verbose display.
EOF

  exit 
}

#------------------------------------------------------------------------- 
function lowercase
{
  [ "$DEBUG" = TRUE ] && set -x

  echo "$*"|tr '[A-Z]' '[a-z]'
}

#------------------------------------------------------------------------- 
function rotate
{
  [ "$DEBUG" = TRUE ] && set -x

  if [ $# -lt 3 ]
  then
     echo "Incorrect parameters to function rotate" >&2
     echo "USAGE: rotate <logfile> <copies> [daily] [weekly <weekday>] [monthly <day>] [pre-processing] [post-processing]" >&2
     return 1
  else
     LOG=$1
     COPIES=$2
     TYPE=$3
     DAY=$4     
     PRE=$5
     POST=$6
  fi

  if [ "$TYPE" != daily -a "$TYPE" != weekly -a $TYPE != monthly ]
  then
     echo "Incorrect rotation type: $TYPE" >&2
     echo "Must be either daily, weekly or monthly" >&2
     return 1
  fi

  case "$TYPE" in
  daily)        swap $LOG $COPIES
		;;
  weekly)       if [ -z "$DAY" ] 
		then
   		   echo "No weekday specified for weekly rotation" >&2
   		   return 1
		fi

		if [ $TODAY = $DAY ]
		then
   		   swap $LOG $COPIES
		fi
		;;
  monthly)      if [ -z "$DAY" ]
		then
                   echo "No day of the month specified for monthly rotation" >&2
		   return 1
		fi

		if [ $DAY -lt 1 -o $DAY -gt 31 ]
        	then
   		   echo "Monthly day: $DAY out of range" >&2
   		   return 1
		fi

		if [ $DAY = $DAYOFM ]
		then
   		   swap $LOG $COPIES
		fi
		;;
  *)            echo "Incorrect rotation type, must be daily, weekly or monthly" >&2
		return 1
		;;
  esac
}

#--------------------------------------------------------------------------
function swap 
{
  [ "$DEBUG" = TRUE ] && set -x

  LOG=$1
  COPIES=$2

  typeset -i count=$COPIES-2 

  if [ -f $LOG ]
  then
     [ "$VERBOSE" = TRUE ] && echo "Rotating $LOG.  Keeping $COPIES copies"
     [ "$PRE" != "" -a "$PRE" != "-" ] && eval "$PRE $LOG"
     while [ $count -ge 0 ]
     do
       if [ -f $LOG.$count.gz ]
       then
          let newlog=$count+1
          mv $LOG.$count.gz $LOG.$newlog.gz
       elif [ -f $LOG.$count ]
       then
          let newlog=$count+1
          $GZIP -f $LOG.$count
          if [ $? -eq 0 ]
          then
            mv $LOG.$count.gz $LOG.$newlog.gz
          else
            echo "$0: compress of $LOG.$count failed; moving uncompressed" >&2
            mv $LOG.$count $LOG.$newlog
          fi
       fi
       let count=$count-1
    done
    cp -p $LOG $LOG.0
    if [ $? -eq 0 ]
    then
      >$LOG
      [ "$POST" != "" -a "$POST" != "-" ] && eval "$POST $LOG.0"
      $GZIP -f $LOG.0
    else
      echo "$0: copy to $LOG.0 failed; log left intact" >&2
    fi
  else
     echo "$0: $LOG does not exist" >&2
  fi
}
#--------------------------------------------------------------------------
#                               END OF FUNCTIONS
#==========================================================================     
# 
# Check for any flags parsed in
#
while getopts :Dhf:v opt
do
  case $opt in
  D)    set -x
	DEBUG=TRUE
	;;
  f)    CONFIG=$OPTARG
	;;
  h)    help
	;;
  v)    VERBOSE=TRUE
	;;
 \?)    echo "Invalid option" >&2
	echo "$USAGE" >&2
	exit 1
	;;
  esac
done

#
# Sanity checks
#
if [ ! -f $CONFIG ]
then
   echo "Error, $CONFIG does does exist" >&2
   exit 1
fi

if [ ! -x $GZIP ]
then
   echo "$GZIP not found or not executable" >&2
   exit 1
fi

# 
# Make sure day is in lowercase for comparisons
#
TODAY=`lowercase $TODAY`

#
# Read files to rotate from configuration file
#
IFS="	"
sed "/^#/D" $CONFIG|sed "/^$/D"|
while read file copies when day pre post
do
  when=`lowercase $when`
  day=`lowercase $day`
  rotate $file $copies $when $day $pre $post
done
 
#
# Send a SIGHUP to syslog daemon
#
if [ -f /etc/syslog.pid ] 
then 
   kill -1 `cat /etc/syslog.pid`
else
   echo "Not known how to restart syslogd on this system" >&2
fi