几个简单的shell,刚学,让大家见笑了

1.加法运算,调用bc就可以实现浮点数的运算了,不过还不会判断是否是浮点数,所以没有加进去判断,大家谁会请指教!!!
#!/bin/bash
sum=0
if (( $# < 2 )) #[ $# -le 2 ]
then
echo "please input two or more parametar!!!"
else
for i in $* #while (( $# > 0 )) until (( $# <= 0 ))
do
sum=`echo "scale=3; $sum + $i" | bc` #shift shift
done #done done
echo "the sum =$sum"
fi


2.实现简单的旋转
#!/bin/bash
carryon=Y
while [ $carryon = Y ]
do
echo -en "-"
sleep 1
echo -en "\b"
echo -en "|"
sleep 1
echo -en "\b"
done

3.创建一个文件夹,如果文件夹存在,询问用户是否撤除.
#/bin/bash
mycontinue=y
while [ $mycontinue = y ]
do
echo -n "input dirname: "
read mydirname
if [ -d $mydirname ] #test whether the name is a existed directory,
#then return true else false
then
echo -n "The directory is already exist!Delete it?y/n: "
temp=y
read eqtemp
while [ $eqtemp = y ]
do
rmdir $mydirname
echo "Delete suclearcase/" target="_blank" >ccsessfully!"
break
done
else
mkdir $mydirname
echo "Create successfully!"
fi
echo -n "continue?y/n:"
read mycontinue
done

原文转自：http://www.ltesting.net