make-backup

#!/bin/bash
set -e

set_dir () { DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"; }; set_dir
safe_source () { source $1; set_dir; }

if [[ $(id -u) > 0 ]]; then sudo $0 "$@"; exit; fi

safe_source $DIR/aktos-bash-lib/basic-functions.sh
safe_source $DIR/aktos-bash-lib/fs-functions.sh
safe_source $DIR/aktos-bash-lib/btrfs-functions.sh

show_help () {
    cat <<HELP

    Usage:

        $(basename $0) ...options...

    Options:

    --source         : source directory for backup
    --backups        : backup container directory
    --method         : method for backup. One of:

                        * hardlinks
                        * btrfs

HELP
}

die () {
    errcho "ERROR: "
    errcho "ERROR: $@"
    errcho "ERROR: "
    show_help
    exit 255
}

source_dir=
backup_dir=
method=
while :; do
    case $1 in
        -h|-\?|--help)
            show_help    # Display a usage synopsis.
            exit
            ;;
        --source)       # Takes an option argument; ensure it has been specified.
            if [ "$2" ]; then
                source_dir=$(realpath $2)
                shift
            else
                die '"--source" requires a non-empty option argument.'
            fi
            ;;
        --backups)       # Takes an option argument; ensure it has been specified.
            if [ "$2" ]; then
                backup_dir=$(realpath $2)
                shift
            else
                die '"--backups" requires a non-empty option argument.'
            fi
            ;;
        --method)       # Takes an option argument; ensure it has been specified.
            if [ "$2" ]; then
                method=$2
                shift
            else
                die '"--method" requires a non-empty option argument.'
            fi
            ;;
        -?*)
            printf 'WARN: Unknown option (ignored): %s\n' "$1" >&2
            ;;
        *)               # Default case: No more options, so break out of the loop.
            break
    esac

    shift
done

[[ "$method" == "hardlinks" ]] || [[ "$method" == "btrfs" ]] || die "method is required."
[[ -d $backup_dir ]] || die "backups should be a directory."
[[ -d $source_dir ]] || die "source should be a directory."

read -p "Enter Comment : " comment
[[ $comment ]] || echo_err "Comment is required."
comment=$(echo $comment | sed -e 's/ /-/g')

prefix=$(get_timestamp)
backup_name="$prefix-$comment"
tmp_name="work-in-progress-$backup_name"


start_timer
if [[ "$method" == "hardlinks" ]]; then
    if ls $backup_dir/work-in-progress* 1> /dev/null 2>&1; then
        echo_err "work in progress directories found. Remove them first."
    fi
    echo "Creating backup with the following name: $backup_name"
    echo "Using hardlinks method"
    cp -al $source_dir $backup_dir/$tmp_name
    mv $backup_dir/$tmp_name $backup_dir/$backup_name
elif [[ "$method" == "btrfs" ]]; then
    is_btrfs_subvolume $source_dir || die "Source should be BTRFS subvolume."
    btrfs sub snap -r "$source_dir" "$backup_dir/$backup_name"
fi
show_timer "Backup completed in:"