DAY20

#!/bin/bash
d=`date +%H`
if [ $d -ge 0 -a $d -lt 7 ]
then
    tag=1
elif [ $d -ge 7 -a $d -lt 12 ]
then
    tag=2
elif [ $d -ge 12 -a $d -lt 18 ]
then
    tag=3
else
    tag=4
fi

case $tag in
    1)
	echo "早晨好"
        ;;
    2)
	echo "上午好"
	;;
    3)
	echo "下午好"
	;;
    4)
	echo "晚上好"
	;;
    *)
	echo "脚本出错啦"
	;;
esac