#!/bin/bashecho "Please input a number"read numexpr $num "+" 10 &> /dev/nullif [ $? -eq 0 ];then echo "$num is a num"else echo "$num not a num"fi这个只能识别整型,浮点数不识别,请问怎样它才能识别浮点数啊?整型和浮点型都识别