Shell Programming and Scripting

#!/bin/bash
#

#Want to enable error log emails?
EMAILLOGS="true"
EMAILTO="me@domain.com"
SUBJECT="Test Script"

#Where to dump errors if EMAILLOGS is false
ERRORLOG="/var/log/backuplog"

##Where are we sending stderr..
if [ $EMAILLOGS != "false" ]; then
        exec 2> >(while read line; do echo -e "$(date):${line}\n"; done >>/tmp/errorlog)
else
        exec 2>>$ERRORLOG
fi

echo -e "**error**\n**error**\n**error**" >&2
sleep 1
echo "piping to the error log for timestamp testing, one second" >&2
sleep 2
echo "two seconds" >&2


#Mail the errorlog if /tmp/backerrors.log exists and is > 0
if [ -s /tmp/errorlog ]; then
        /usr/bin/mail -s "$SUBJECT" "$EMAILTO" < /tmp/errorlog
else
        rm -f /tmp/errorlog
fi

rm -f /tmp/errorlog

#Want to enable error log emails?
EMAILLOGS="true"
EMAILTO="me@domain.com"
SUBJECT="Backup Error Log"

#Where to dump errors if EMAILLOGS is false
ERRORLOG="/var/log/backup/error.log"

#Set some main variables
set $(date)
MOUNTLOC="/mnt/bak"

##What is the root we are reading directories from?
DATA="/mail"

##Which directories do you want to exclude?
EXCLUDE="oldusers"

##What is the root we are writing to?
BACK=$MOUNTLOC

##Mount the NFS I'm backing to
mount $MOUNTLOC

##Variables to check if files exist
WEEKLYFILES=$(ls $BACK/weeklybak/*.tgz 2>/dev/null | wc -l)
INCREMFILES=$(ls $BACK/data_diff/*.tgz 2>/dev/null | wc -l)

##Where are we sending stderr..
if [ $EMAILLOGS == "true" ]; then
        ##This is process substitution: Read in sterr lines,
        ##echo back timstamp: error, then dump into a tmp file for mailing
        exec 2> >(while read line; do echo -e "$(date):${line}\n"; done >/tmp/backerrors.log)
else
        exec 2>>$ERRORLOG
fi

##Script start
TIMESTART=$(date +%Y\/%m\/%d-%H:%M)
printf "*--------------------$TIMESTART--------------------*\n"
if [ "$1" = "Sun" ] || [ "$WEEKLYFILES" = "0" ];  then
        #If it's Sunday, or a full backup doesn't exist, remove incremented files and logs
        if [ "$INCREMFILES" != "0" ];  then
                echo "Purging old incremental files..."
                rm -fv $BACK/data_diff/*.tgz
                rm -fv $BACK/snars/*.snar
        fi
                #Just in case something is left over
                echo "Purging old full backups..."
                rm -fv $BACK/weeklybak/*.tgz

        printf "Running full backup...\n"

        cd $DATA
        for DIRECTORY in $(ls -d *); do
                tar                                                                     \
                        --create --gzip                                                 \
                        --file=$BACK/weeklybak/${DIRECTORY}_$6-$2-$3.tgz                \
                        --listed-incremental=$BACK/snars/${DIRECTORY}_backup.snar       \
                        --exclude="$EXCLUDE"                                            \
                        $DIRECTORY
        done
        cd ~

else
printf "Running incremental backup of emails...\n"
        cd $DATA
        for DIRECTORY in $(ls $DATA); do
                tar                                                                     \
                        --create --gzip                                                 \
                        --file=$BACK/data_diff/${DIRECTORY}_$6-$2-$3.tgz                \
                        --listed-incremental=$BACK/snars/${DIRECTORY}_backup.snar       \
                        --exclude="$EXCLUDE"                                            \
                        $DIRECTORY
        done
        cd ~
fi

        #Grab my scripts and cronjobs
        printf "Grabbing cronjobs and scripts...\n"

        tar                                     \
                --create --gzip                 \
                --file=$BACK/rootscripts.tgz    \
                /root/scripts

        tar                                     \
                --create --gzip                 \
                --file=$BACK/crontabs.tgz       \
                /var/spool/cron/crontabs

#Mail the errorlog if /tmp/backerrors.log exists and is > 0
if [ -s /tmp/backerrors.log ]; then
        /usr/bin/mail -s "$SUBJECT" "$EMAILTO" < /tmp/backerrors.log
else
        rm -f /tmp/backerrors.log
fi

##Define time, now that we've finished
TIMEFINISHED=$(date +%Y\/%m\/%d-%H:%M)

##Log finished time
printf "Finished...\n"
printf "*--------------------$TIMEFINISHED--------------------*\n\n\n"

##Umount the NFS
umount $MOUNTLOC

#Give our mail command time to process, then remove the back up errors
sleep 5
rm -f /tmp/backerrors.log
exit

/usr/bin/mail -s "$SUBJECT" "$EMAILTO" < /tmp/backerrors.log &
wait

sendwait
Wait for the background mailer to finish before returning. The default is nosendwait.