Check for errors

error.sh

check_error()
{
	# Check for an error
	if [ "${1}" -ne "0" ]; then

		# Check for a custom message
		if [ ! -z "${2}" ]; then
			echo "${2}"
		else
			echo "Fatal error"
		fi

		# Exit with the proper code
		exit ${1}
	fi
}

./do-something.sh
check_error $? "Error message"