Backup Incremental v2.0

#!/bin/bash
# full and incremental backup script
# Modified by Antonio Vanegas @hpsaturn

# Created 07 February 2000
# Based on a script by Daniel O'Callaghan <[email protected]>
# and modified by Gerhard Mourani <[email protected]>

# REVISIONS
# 20121219 v2.0 Autoconfigure via console paramaters and secondary storage.

COMPUTER=$1                             # name of this computer
ROOT=$2                                 # target directory
DIRECTORIES=$3                          # directoris to backup
SECONDARY=$4                            # secondary store backup

BACKUPDIR=$ROOT/$COMPUTER               # where to store the backups
TIMEDIR=$ROOT/$COMPUTER/last-full       # where to store time of full backup
TAR=/bin/tar                            # name and locaction of tar
IGNORE=$ROOT/$COMPUTER/ignorefiles      # Archivos a ignorar

PATH=/usr/local/bin:/usr/bin:/bin
DOW=`date +%a`                      # Day of the week e.g. Mon
DOM=`date +%d`                      # Date of the Month e.g. 27
DM=`date +%d%b`                         # Date and Month e.g. 27Sep
DATE=`date +%Y%m%d`                     # Date format AAAAMMDD

# On the 1st of the month a permanet full backup is made
# Every Sunday a full backup is made - overwriting last Sundays backup
# The rest of the time an incremental backup is made. Each incremental
# backup overwrites last weeks incremental backup of the same name.
#
# if NEWER = "", then tar backs up all files in the directories
# otherwise it backs up files newer than the NEWER date. NEWER
# gets it date from the file written every Sunday.

function showHelp(){
    echo ""
    echo "Usage: backup NameOfBackup RootStorage DirToBackup [SecondaryStorage]"
    echo ""
    echo "Example dual storage: backup home /bkp /home/user /mnt/samba/bkp"
    echo "Example simple:       backup home /bkp /home/user"
    echo ""
    echo "Example: Install in crontab:"
    echo "00  19  *   *   *   /home/user/bin/backup home /bkp /home/user /mnt/samba/bkp"
    echo ""
}

if [ "$COMPUTER" == "" ]; then
    showHelp
    exit 3
fi

if [[ ( "$ROOT" == "" ) || ( "$DIRECTORIES" == "" ) ]]; then
    echo ""
    echo "ERROR: Root backup directory or target directory not found!"
    showHelp
    exit 3
fi

if [ ! -d "$ROOT/$COMPUTER" ]; then
    echo -n "CREATING ROOT BACKUP: $ROOT"
    mkdir -p $ROOT/$COMPUTER
    INITBKP=1
    echo " [OK]"
fi

if [ ! -d "$TIMEDIR" ]; then
    echo -n "CONFIGURE TIME DIRECTORY: $TIMEDIR"
    mkdir -p $TIMEDIR
    NOW=`date +%d-%b`
    echo $NOW > $TIMEDIR/$COMPUTER-full-date
    echo " [OK]"
fi

if [ ! -f "$IGNORE" ]; then
    echo -n "CREATING IGNORE CONFIG FILE: $IGNORE"
    touch $IGNORE
    echo " [OK]"
fi

if [ "$SECONDARY" != "" ]; then

    if [ ! -d "$SECONDARY/$COMPUTER" ]; then
        echo -n "CREATING SECONDARY BACKUP: $SECONDARY"
        mkdir -p $SECONDARY/$COMPUTER
        echo " [OK]"
        echo ""
    fi

fi

# Monthly full backup
if [[( $DOM = "15" ) || ( $INITBKP != "" )]]; then
        NEWER=""
        FILE=$BACKUPDIR/bkp_$COMPUTER_$DATE.tar.gz
        if [ -f $FILE ]; then
          rm $FILE
        fi

        $TAR $NEWER -zcf $FILE --exclude-from=$IGNORE $DIRECTORIES

        if [ -d "$SECONDARY/$COMPUTER" ]; then
            cp -f $FILE $SECONDARY/$COMPUTER/
        fi
fi

# Weekly full backup
if [ $DOW = "Fri" ]; then
        NEWER=""
        NOW=`date +%d-%b`

        # Update full backup date (/tmp for samba)
        echo $NOW > /tmp/$COMPUTER-full-date
        mv /tmp/$COMPUTER-full-date $TIMEDIR/
        # remove file if exist
        FILE=$BACKUPDIR/$COMPUTER-$DOW.tar.gz
        if [ -f $FILE ]; then
          rm $FILE
        fi

        $TAR $NEWER -zcf $FILE --exclude-from=$IGNORE $DIRECTORIES

        if [ -d "$SECONDARY/$COMPUTER" ]; then
            cp -f $FILE $SECONDARY/$COMPUTER/
        fi

# Make incremental backup - overwrite last weeks
else
        # Get date of last full backup
        NEWER="--newer `cat $TIMEDIR/$COMPUTER-full-date`"
        # remove file if exist
        FILE=$BACKUPDIR/$COMPUTER-$DOW.tar.gz
        if [ -f $FILE ]; then
          rm $FILE
        fi

        $TAR $NEWER -zcf $FILE --exclude-from=$IGNORE $DIRECTORIES

        if [ -d "$SECONDARY/$COMPUTER" ]; then
            cp -f $FILE $SECONDARY/$COMPUTER/
        fi
fi