if

[root@es3 data]# cat ifaction.sh
#!/bin/bash
#********************************************************************
read -p "请输入身高(m为单位): " HIGH

if [[ ! "$HIGH" =~ ^[0-2](\.[0-9]{,2})?$ ]];then
echo "输入错误的身高!"
exit 1
fi

read -p "请输入体重(kg为单位): " WEIGHT

if [[ ! "$WEIGHT" =~ ^[0-9]{1,3}$ ]];then echo "输入错误的体重!"; exit 2; fi

BMI=`echo $WEIGHT/$HIGH^2|bc`

if [ $BMI -le 18 ] ;then
echo "太瘦了,多吃点!"
elif [ $BMI -lt 24 ] ;then
echo "身材很棒!"
else
echo "太胖了,注意节食,加强运动!"
fi