Listing 1: Log file monitoring script

#! /bin/sh
# @(#)util/savelog.sh   1.5 7/11/92 11:40:30 
#
# savelog - save a log file
#
#    Copyright (C) 1987, 1988 Ronald S. Karr and Landon Curt Noll 
#    Copyright (C) 1992  Ronald S. Karr
# 
     
# common location
PATH="/sbin:/usr/sbin:/bin:/usr/bin:/usr/local/bin"; export PATH 
COMPRESS="compress"
COMP_FLAG="-f"
DOT_Z=".Z"
CHOWN="chown"
GETOPT="getopt"
     
# parse args
exitcode=0      # no problems to far 
prog=$0
mode=
user=
group=
touch=
count=7
set -- `$GETOPT m:u:g:c:lt $*`
if [ $# -eq 0 -o  $? -ne 0 ]; then
        echo "usage: $prog [-m mode][-u user][-g group][-t][-c cycle][-l] file
..." 1>&2
        exit 1
fi
for i in $*; do
        case $i in
        -m) mode=$2; shift 2;;
        -u) user=$2; shift 2;;
        -g) group=$2; shift 2;;
        -c) count=$2; shift 2;;
        -t) touch=1; shift;;
        -l) COMPRESS=""; shift;;
        --) shift; break;;
        esac
done
if [ "$count" -lt 2 ]; then
        echo "$prog: count must be at least 2" 1>&2 
        exit 2
fi
     
# cycle thru filenames
while [ $# -gt 0 ]; do
     
        # get the filename
        filename=$1
        shift
     
        # catch bogus files
        if [ -b "$filename" -o -c "$filename" -o -d "$filename" ]; then
                echo "$prog: $filename is not a regular file" 1>&2 
                exitcode=3
                continue
        fi
     
        # if not a file or empty, do nothing major 
        if [ ! -s $filename ]; then
                # if -t was given and it does not exist, create it 
                if [ ! -z "$touch" -a ! -f $filename ]; then 
                        touch $filename
                        if [ "$?" -ne 0 ]; then
                                echo "$prog: could not touch $filename" 1>&2 
                                exitcode=4
                                continue
                        fi
                        if [ ! -z "$user" ]; then 
                                $CHOWN $user $filename
                        fi
                        if [ ! -z "$group" ]; then 
                                chgrp $group $filename
                        fi
                        if [ ! -z "$mode" ]; then 
                                chmod $mode $filename
                        fi
                fi
                continue
        fi
     
        # be sure that the savedir exists and is writable 
        savedir=`expr "$filename" : '\(.*\)/'`
        if [ -z "$savedir" ]; then
                savedir=./OLD
        else
                savedir=$savedir/OLD
        fi
        if [ ! -s $savedir ]; then
                mkdir $savedir
                if [ "$?" -ne 0 ]; then
                        echo "$prog: could not mkdir $savedir" 1>&2 
                        exitcode=5
                        continue
                fi
                chmod 0755 $savedir
        fi
        if [ ! -d $savedir ]; then
                echo "$prog: $savedir is not a directory" 1>&2 
                exitcode=6
                continue
        fi
        if [ ! -w $savedir ]; then
                echo "$prog: directory $savedir is not writable" 1>&2 
                exitcode=7
                continue
        fi
     
        # deterine our uncompressed file names 
        newname=`expr "$filename" : '.*/\(.*\)'` 
        if [ -z "$newname" ]; then
                newname=$savedir/$filename
        else
                newname=$savedir/$newname
        fi
     
        # cycle the old compressed log files 
        cycle=`expr $count - 1`
        rm -f $newname.$cycle $newname.$cycle$DOT_Z 
        while [ "$cycle" -gt 1 ]; do
                # --cycle
                oldcycle=$cycle
                cycle=`expr $cycle - 1`
                # cycle log
                if [ -f $newname.$cycle$DOT_Z ]; then
                        mv -f $newname.$cycle$DOT_Z $newname.$oldcycle$DOT_Z
                fi
                if [ -f $newname.$cycle ]; then
                        # file was not compressed for some reason move it anyway 
                        mv -f $newname.$cycle $newname.$oldcycle
                fi
        done
     
        # compress the old uncompressed log if needed 
        if [ -f $newname.0 ]; then
                if [ -z "$COMPRESS" ]; then
                        newfile=$newname.1
                        mv $newname.0 $newfile
                else
                        newfile=$newname.1$DOT_Z
                        $COMPRESS $COMP_FLAG < $newname.0 > $newfile 
                        rm -f $newname.0
                fi
                if [ ! -z "$user" ]; then 
                        $CHOWN $user $newfile
                fi
                if [ ! -z "$group" ]; then 
                        chgrp $group $newfile
                fi
                if [ ! -z "$mode" ]; then 
                        chmod $mode $newfile
                fi
        fi
     
        # move the file into the file.0 holding place 
        mv -f $filename $newname.0
     
        # replace file if needed
        if [ ! -z "$touch" -o ! -z "$user" -o \
             ! -z "$group" -o ! -z "$mode" ]; then 
                touch $filename
        fi
        if [ ! -z "$user" ]; then 
                $CHOWN $user $filename
        fi
        if [ ! -z "$group" ]; then 
                chgrp $group $filename
        fi
        if [ ! -z "$mode" ]; then 
                chmod $mode $filename
        fi
     
        # fix the permissions on the holding place file.0 file 
        if [ ! -z "$user" ]; then 
                $CHOWN $user $newname.0
        fi
        if [ ! -z "$group" ]; then 
                chgrp $group $newname.0
        fi
        if [ ! -z "$mode" ]; then 
                chmod $mode $newname.0
        fi
done
exit $exitcode

# End of File