Create or update tar.gz archive based on version file

#!/bin/bash
# Purpose:
# * Find version file ("version").
# * Backup files in same directory.
# * Create or update tar.gz archive based on version file.

# Copyright (C) 2012  Savvas Radevic <vicedar@gmail.com>
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# TEST CASE -- This command will create the required tree output of folder/files
# dir=Parent; mkdir -p $dir; for z in {Vol1,Vol2,Vol3}; do for x in {D009,D010,S060,T020}; do echo $dir/$z/$x; mkdir -p $dir/$z/$x; for i in {xls,gif,vsd,mpp,mdb,html}; do echo $dir/$z/$x/${x}_v1.$i; echo $dir/$z/$x/${x}_v2.$i; touch $dir/$z/$x/${x}_v1.$i; touch $dir/$z/$x/${x}_v2.$i; done; echo $dir/$z/$x/version; echo 1 > $dir/$z/$x/version; done; done

DST_DIR=~/Desktop/testme/Output/zipped
SRC_DIR=~/Desktop/testme/Parent/Vol*/*
VERSION_FILE=version
DT=`date +%Y%m%d%H`

#Create DST_DIR
mkdir -p $DST_DIR

echo "*** Checking if files/folders exist: $DST_DIR"
ls -ld $DST_DIR
echo "*** Checking if files/folders exist: $SRC_DIR"
ls -ld $SRC_DIR

#Search directory $d for files (-type f) that match (-name) "$VERSION_FILE"
for ver in `find $SRC_DIR -type f -name "$VERSION_FILE"`; do
    #ver is file path of "version"
    echo -e "\n\n\n=== Processing version file ==="
    echo "*** Version file: $ver"
    #dirname is directory path of file "version"
    dirname=`dirname $ver`
    echo "*** dirname: $dirname"
    #Read first character only from $ver file
    version=`head --bytes=1 $ver`
    echo "*** version: $version"
    #Search directory dirname for files (-type f) that match (-name) "*_v${version}*"
    for f in `find $dirname -type f -name "*_v${version}*"`; do
        #dirpathname and cleanname are used for file naming the tgz file
        dirpathname=`echo $dirname | rev | cut -d / -f1,2 | rev | sed 's/\//-/'`
        echo "*** dirpathname: $dirpathname"
        cleanname=`echo $f | cut -d / -f 2 | cut -d _ -f 1`
        echo "*** cleanname: $cleanname"
        echo "*** Checking if files/folders exist"
        ls -ld $f
        backupfilepath="$DST_DIR/Proc_Sat-1-${DT}-S515-V${version}-OUNCL-P${dirpathname}-${cleanname}.tar.gz"
        echo "*** backup file path: $backupfilepath"
        # If backup file exists, append new files
        if [ -e $backupfilepath ]; then
            # u = update, z = gzip, v=verbose, f=filename
            # Note: tar --update does not allow to update gzipped files,
            # we unzip and rezip them.
            echo "*** backup file exists"
            # backupfiletar is .tar file path (stripped .gz from backupfilepath)
            backupfiletar="`echo -n $backupfilepath | head --bytes -3`"
            echo "*** backupfiletar: $backupfiletar"
            echo "*** decompressing"
            gunzip -vfd $backupfilepath
            if [ ! -f ${backupfiletar} ]; then
                echo "*** Error during backup"
                exit 1
            fi
            echo "*** updating"
            tar uvpf ${backupfiletar} $f
            if [ $? -ne 0 ]; then
                echo "*** Error during backup"
                exit 1
            fi
            echo "*** recompressing"
            gzip -vf9 ${backupfiletar}
            if [ ! -f ${backupfilepath} ]; then
                echo "*** Error during backup"
                exit 1
            fi
        else
            echo "*** backup file doesn't exist, creating a new backup file"
            # c = create
            tar czvpf $backupfilepath $f
            if [ $? -ne 0 ]; then
                echo "*** Error during backup"
                exit 1
            fi
        fi
        echo "*** Checking if backup file was created"
        ls -ld $backupfilepath
        echo -e "*** Done\n"
    done
done