simple script to backup a directory as a tar.gz archive

backup-dir.sh

#!/bin/bash
OUT_DIR=/opt/DUMP
VERBOSE=0
NAME=

show_help() {
cat <<HELP
Backs up a directory.
Usage: $0 [-h -?] [-n name] [-o outdir] <directory> [...tar options]

        -h, -?       Show this help.
        -n name      Use 'name' as the prefix for the backup archive.
        -o outdir    Output archive to 'outdir'. Default: $OUT_DIR.
        tar options  Passed as-is to tar.
HELP
}

while getopts "h?vo:n:" OPT; do
    case "$OPT" in
    h|\?)
        show_help
        exit 0
        ;;
    v)
        VERBOSE=1
        ;;
    o)
        OUT_DIR=$OPTARG;
        ;;
    n)
        NAME=$OPTARG
        ;;
    esac
done
shift $((OPTIND-1))

DIR=$1
shift 1

if [ -z $NAME ]; then
        NAME=`echo $DIR | sed 's/[^a-zA-Z0-9]\+/-/g' | sed 's/\(^-\|-$\)//g'`
fi

# delete old backups (older than two days)
PREFIX=$OUT_DIR/${NAME}-backup-
find ${PREFIX}*.gz -mtime +2 -exec rm "{}" \;

# find name for new backup
FN=${PREFIX}`date +'%Y-%m-%d'`
if [ -f $FN.gz ]; then
        J=1
        while [ -f $FN-$J.gz ]; do
                J=$((J+1))
        done
        FN=$FN-$J.gz
else
        FN=$FN.gz
fi

tar czf $FN $DIR "$@"
chmod 640 $FN