幾個簡單的shell,剛學,讓大家見笑了

1.加法運算,調用bc就可以實現浮點數的運算了,不過還不會判斷是否是浮點數,所以沒有加進去判斷,大家誰會請指教!!!
#!/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.實現簡單的旋轉
#!/bin/bash
carryon=Y
while [ $carryon = Y ]
do
echo -en "-"
sleep 1
echo -en "\b"
echo -en "|"
sleep 1
echo -en "\b"
done

3.創建一個文件夾,如果文件夾存在,詢問用戶是否撤除.
#/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

原文轉自：http://www.kjueaiud.com