#!/usr/bin/env dash

match="/some/test/path/"
default_name="root"
uid_max="65534"

read -p "Enter chmod user  or UID (default: $default_name): "  -r chuser
read -p "Enter chmod group or UID (default: $default_name): "  -r chgroup

chuser="${chuser:-$default_name}"
chgroup="${chgroup:-$default_name}"

# result is a boolean 0 or 1; 1 means value out of permitted range
iduser="$((chuser + 0 > uid_max))" 2>/dev/null
# shellcheck disable=SC2181
if [ $? -ne 0 ]; then
	# Illegal Number; possibly a username
	if ! getent passwd "$chuser" >/dev/null; then
		>&2 printf "Error: '%s' does not exist\n" "$chuser"
		exit 1
	fi
fi
if [ $iduser -eq 1 ]; then
 >&2 printf "Error: maximum user ID is %d\n" "$uid_max"
 exit 2
fi


# result is a boolean 0 or 1; 1 means value out of permitted range
idgroup="$((chgroup + 0 > uid_max))" 2>/dev/null
# shellcheck disable=SC2181
if [ $? -ne 0 ]; then
	# Illegal Number; possibly a username
	if ! getent group "$chgroup" >/dev/null; then
		>&2 printf "Error: '%s' does not exist\n" "$chgroup"
		exit 3
	fi
fi
if [ $idgroup -eq 1 ]; then
 >&2 printf "Error: maximum group ID is %d\n" "$uid_max"
 exit 4
fi

# at this point both chuser and chgroup are either existing names or valid numeric IDs
chmod --recursive u=rwX,g=rX,o-rwx "$(dirname "$match")"
chown --recursive "$chuser:$chgroup" "$(dirname "$match")"