shell編程之循環結構——猜數程序

#!/bin/bash
##filename:guest_number.sh
#對被猜中的樹num進行賦值
#$RANDOM是一個系統隨機數的環境變量，模100運算用於生成1~100的隨機整數
num=$((RANDOM%100))
#使用永真循環，條件退出的方式接收用戶猜測並進行判斷
while [ 1 ];do
read -p "Please input a number:" user_num
if [ $user_num -lt $num ]; then
echo "The number you inputed is less then my NUMBER."
elif [ $user_num -gt $num ]; then
echo "The number you inputed is greater then my NUMBER."
elif [ $user_num -eq $num ]; then 
echo "Congratulate:my NUMBER is $num."
break
fi

done

break提供了以下兩種循環控制語句

1).break：用來跳出循環

2).continue:只會跳過本次循環，忽略本次循環剩餘的代碼，進入循環的下一次迭代