#!/bin/bash
#
# Quick and dirty script to insert a slice into a binary file
# Copyright (C) 2016 Hamish Coleman
#
# TODO:
# - a tool that is portable to Windows
# - should output dependancy information

INFOFILE="$1"
if [ ! -r "$INFOFILE" ]; then
    echo Need file with source and offset info
    exit 1
fi
shift

INPUT="$1"
if [ -z "$INPUT" ]; then
    echo Need input filename
    exit 1
fi
shift

OUT="$1"
if [ -z "$OUT" ]; then
    echo Need output filename
    exit 1
fi

read SOURCE OFFSET LENGTH <"$INFOFILE"

set -x

cp --reflink=auto $SOURCE $OUT
dd status=none if=$INPUT bs=$[$LENGTH] count=1 | dd status=none conv=notrunc bs=$[$OFFSET] seek=1 of="$OUT"