Basic backup script using tar

If you are looking for a simple backup script using tar then the below script is enough.

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#!/bin/sh
# full and incremental backup script
# created 07 February 2000
# Based on a script by Daniel O'Callaghan 
# and modified by Gerhard Mourani 

#Change the 5 variables below to fit your computer/backup

COMPUTER=deep                            # name of this computer
DIRECTORIES="/home"                      # directoris to backup
BACKUPDIR=/backups                       # where to store the backups
TIMEDIR=/backups/last-full               # where to store time of full backup
TAR=/bin/tar                              # name and locaction of tar

#You should not have to change anything below here

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

# 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.


# Monthly full backup
if [ $DOM = "01" ]; then
    NEWER=""
    $TAR $NEWER -cf $BACKUPDIR/$COMPUTER-$DM.tar $DIRECTORIES
fi

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

    # Update full backup date
    echo $NOW > $TIMEDIR/$COMPUTER-full-date
    $TAR $NEWER -cf $BACKUPDIR/$COMPUTER-$DOW.tar $DIRECTORIES

# Make incremental backup - overwrite last weeks
else

    # Get date of last full backup
    NEWER="--newer `cat $TIMEDIR/$COMPUTER-full-date`"
    $TAR $NEWER -cf $BACKUPDIR/$COMPUTER-$DOW.tar $DIRECTORIES
fi
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