#!/bin/sh get_magic_word() { dd if=$1 bs=4 count=1 2>/dev/null | od -A n -N 4 -t x1 | tr -d ' ' } get_fs_type() { local magic_word="$(get_magic_word "$1")" case "$magic_word" in "3118"*) echo "ubifs" ;; "68737173") echo "squashfs" ;; *) echo "unknown" ;; esac } round_up() { echo "$(((($1 + ($2 - 1))/ $2) * $2))" }