#!/bin/sh

squashfs_size_ratio()
{
  local fn="$1"
  #FSIZE="$(stat -c "%s" "$fn")"
  word5() { echo $5; }
  FSIZE="$(word5 `ls -l "$fn"`)"
  echo $(( $FSIZE * 3367 / 1000 ))
}

squashfs_size_magicdb()
{

  get()
  {
    local len=$1
    local off=$2
    local fn="$3"
    #local OUT=( $(od -t d$len -N$len -j $off "$fn") )
    #echo "${OUT[1]}"
    od -t u$len -N$len -j $off "$fn" | head -n1 |  sed 's/.* //'
  }

#   getReversedEndian()
#   {
#     local len=$1
#     local off=$2
#     local fn="$3"
#     #local B=( $(od -t x$len -N$len -j $off "$fn") )
#     #B="${B[1]}"
#     local B="$(od -t x$len -N$len -j $off "$fn" | head -n1 | cut -d' ' -f2)" 
#     local D=
#     local C=$(( $len * 2 ))
#     while [ $C -gt 0 ]
#     do
#       C=$(( $C - 2 ))
#       D="$D${B:$C:2}"
#     done
#     D="0x$D"
#     echo $D
#   }
  getReversedEndian()
  {
    local len=$1
    local off=$2
    local fn="$3"
    local D=
    local C=$len 
    while [ $C -gt 0 ]
    do
      C=$(( $C - 1 ))
      D="$(od -t x1 -N1 -j $(($off+$C)) "$fn" | head -n1 | cut -d' ' -f2)$D" 
    done
    D=$((0x$D))
    echo $D
  }


  local fn="$1"

  local M=$(get 4 0 "$fn")
  local N=$(getReversedEndian 4 0 "$fn")
  if [ $M -eq 1936814952 ]
  then
    # Proper endian.
    local get=get
  elif [ $N -eq 1936814952 ]
  then
    # Reversed endian.
    local get=getReversedEndian
  else
    error not squashfs
  fi

  local T=$($get 2 28 "$fn")
  if [ $T -lt 3 ]
  then
    local BC=$($get 4 8 "$fn") 
  else
    local BC=$($get 8 63 "$fn")
  fi

  echo $BC
}


squashfs_size_ratio "$1"