#!/bin/bash
#
# bakit.sh
#
# Copyright (C) 2010, Branko Majic <branko@majic.rs>
#
# 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/>.
#

program="bakit.sh"
version="0.1"

function usage() {
    cat <<EOF
$program $version, a non-interactive utility for creating local on-system
backups of files.

Usage: $program [OPTIONS] file

$program is a non-interactive utility for creating local on-system backups of
files. Its primary use is for the various configuration files found on most of
the systems. It allows you to easily create a timestamped backup of files
specified as input arguments.

$program accepts the following options:

    -v        show script version and licensing information
    -h        show usage help


Please report bugs and send feature requests to <branko@majic.rs>.
EOF
}

function version() {
        cat <<EOF
$program, version $version

+-----------------------------------------------------------------------+
| Copyright (C) 2010, Branko Majic <branko@majic.rs>                    |
|                                                                       |
| 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/>. |
+-----------------------------------------------------------------------+

EOF
}

# If no arguments were given, just show usage help.
if [[ -z $1 ]]; then
    usage
    exit 0
fi

# Parse the arguments
while getopts "vh" opt; do
    case "$opt" in
        v) version
           exit 0;;
        h) usage
           exit 0;;
        *) usage
           exit 1;;
    esac
done
i=$OPTIND
shift $(($i-1))

# Create a backup of each provided file
while [[ -n $1 ]]; do
    source="$(echo "$1" | sed -e 's#/\+$##' )"
    bakFile="${source}.bak.$(date +%Y%m%d)"

    # Generate a new name for the backup, making sure the old ones do not get
    # overwritten
    let i=1
    while [[ -e "$bakFile" ]]; do
        bakFile="${source}.bak.$(date +%Y%m%d).$i"
        let i=i+1
    done

    cp -pr "$source" "$bakFile"
    shift
done