#!/bin/bash
 
  mirror_rootfs () {
    [[ ! $(command -v rsync) ]] && { echo rsync must be installed to use this function; return 5; }
    dr="--dry-run"

    dest=$(realpath -s $1)
    rootfs=$(realpath -s "${2:-/}")

    [ ! -d "$dest" ] && echo destination $dest is not a directory && return 3
    [ ! -d "$rootfs/etc" ] && echo not root filesystem at $rootfs && return 3

    echo making mirror of root filesystem to 
    rfse=rootfs_excludes
    if sudo rsync -axHAWXS $dr --numeric-ids --delete --delete-excluded --force --exclude-from="$(rootfs_excludles)"  / /mnt/adrive/nas/@rootfs; then
        echo making mirror of boot partition to /mnt/adrive/nas/@rootfs
        if sudo rsync -axHAWXS $dr --numeric-ids --force --delete  /boot/ /mnt/adrive/nas/@boot; then
        echo doit
        else 
            echo unable to sync a copy of /boot, aborted backup    
        fi
    else
        echo unable to sync a copy of root file system, backkup failed
    fi
}

rootfs_excludes () {

local list; local delete
[[ $1 == "-l" ]] && list=true && shift   
[[ $1 == "-r" ]] && delete=true && shift
[[ "$1" == "-"* ]] && >&2 echo bad option, aborting && return 1
rfse=${1:-/tmp/rootfs_excludes.lst}
[[ $delete ]] && rm $rfse
cat <<EOF > $rfse
.[Tt]rash*
tmp/
cache/
log/
log[s]/
lost+found
EOF
if [[ $list ]];then
    cat $rfse; rm -f $rfse  
    else
    echo $rfse
fi
}

mountpoints () {
cat /proc/mounts | cut -d ' ' -f2 | sort
}