1.比较两个数的大小：
echo -n "please input the firt number:"
read first
echo -n "please input the second number:"
read second
if [ $first -gt $second ]
then
echo "$first is the bigger one !"
elif [ $first -lt $second ]
then
echo "$second is the bigger one !"
else
echo "they are equal !"
fi
2.模拟登陆以及下一步：
echo -n "login:"
read name
echo -n "password:"
read -s passwd
if [ $name = "abc" -a $passwd = "123" ]
then
echo "the host and password is right!"
read -n1 -p "do you want to continue (Y/N)?" answer
echo
case $answer in
y | Y)
echo "fine,continue"
;;
n | N)
echo "ok, byebye"
;;
*)
echo "the input is illegal !!!"
;;
esac
#exit 0
else
echo "the name or password is wrong !"
fi
3.另类自然数求和
sumnum.sh
#!/bin/bash
# echo "please entre your number:"
# read num
for (( i=1;i<=$1;i++ ));
do
echo $i;
done
sh sumnum.sh 100 | echo $[ $( tr '\t' '+') 0]
