Linux编程_Shell脚本练习题

#! /bin/bash

sum=0
for i in `seq 1 100`;do
        sum=$[$i+$sum]
done
echo $sum

#! /bin/bash

n=0
while [$n -lt "1"];do
        read -p "Please input a number:"n
done

sum=0
for i in `seq 1 $n`;do
        sum=$[$i+$sum]
done
echo $sum

#! /bin/bash

groupadd users
for i in `seq -w 0 99`;do
        uesradd -g users user_0$i4
done

#! /bin/bash

for((i=1;i<20;i++));
do
if(i<10);then
jsj="jsj0$i";
else
jsj="jsj$i";
fi
useradd $jsj
done

#! /bin/bash

echo -n your choice:
read choice
case $choice in
[g,G]
echo "She is a girl."
;;
[b,B]
ehco "He is a boy."
;;
*)
echo "I don‘t know."
;;
esac

#! /bin/bash

read -p "imput num1:"a
read -p "input num2:"b
read -p "input operator:"o
case $o in
+)let "res=a+b"
echo $res;;
-)let "res=a-b"
echo $res;;
/)awk‘BEGIN{printf %.2f\n",‘$a‘/‘$b‘}‘;;
*)let "res=a*b"
echo $res;;
esac