#!/bin/sh

verbose=true

while [ "$*" != "" ] ; do
	case $1 in
		-q) verbose=false ; shift;;
		*) break ;;
	esac
done

if [ $# -ne 1 ] ; then
	echo Usage: "$0 [ -q ] target" >&2
	exit 22
fi

target="$1"
prefix=/sys
set -e

set -- /class/hwmon

while [ -n "$1" ] ; do
	source="$1" ; shift
	src="$prefix$source"
	tgt="$target$source"
	if [ -e "$tgt" ] ; then
		! $verbose || echo "$tgt already exists"
		continue
	fi
	if [ -L "$src" ] ; then
		link="$(readlink "$src")"
		! $verbose || echo "$tgt -> $link"
		ln -s "$link" "$tgt"
		link="/$(realpath --relative-to="$prefix" -s "$(dirname "$src")"/"$link")"
		set -- "${link}" "$@"
		continue
	fi
	if [ -d "$src" ] ; then
		! $verbose || echo "$tgt/"
		mkdir -p "$tgt"
		sub="$(ls -A "$src")" # cannot use a pipeline, it creates new parameter scope
		while [ -n "$sub" ] ; do
			x=$(echo "$sub" | head -n 1)
			sub="$(echo "$sub" | tail -n +2)"
			[ "$x" != autosuspend_delay_ms ] || continue # these files cause io error
			set -- "$source/$x" "$@"
		done
		continue
	fi
	if [ -f "$src" ] ; then
		! $verbose || echo "$tgt"
		if [ -r "$src" ] ; then
			cp -a "$src" "$tgt" ||: # some files gitve i/o error even when readable
		else
			! $verbose || echo "$tgt not readable"
			touch --reference="$src" "$tgt"
			chmod --reference="$src" "$tgt"
		fi
		continue
	fi
done

exit 0