if语句的基本用法举例

1.输入分数，60以下失败，60-80不错，80-100NB!

#!/bin/bash

#**************************************************
#Author：     Du_shan
#QQ：         316722220 
#Date：       2018-08-30        
#FileName:    score_60.sh
#URL:         https://blog.csdn.net/weixin_40001704
#Description: The script test
#Copyright(C):2018 all rights reserved
#**************************************************
read -p "please input your score:" score
if [[ "$score" =~ ^[[:digit:]]+$ ]] ;then
        true
else
        echo "please input a digit"
        exit 60
fi


if  [ "$score" -ge 0 -a "$score" -le 60 ];then
        echo "fail"
elif [ "$score" -gt 60 -a "$score" -le 80 ];then
        echo "GOOD!"
elif [ "$score" -gt 80 -a "$score" -le 100 ];then
        echo "NB"
else
        echo "wrong score" 
fi

---

 

2.询问是否有钱，有钱你就赢了；没钱继续询问是不是帅，帅的话，小白脸儿你赢了；不帅还每钱，那等什么骚年，努力工作吧！

#!/bin/bash
#
#**************************************************************
#Author：                 Dadda_Du
#QQ：                     316722220
#Date：                   2018-08-31
#FileName：               ask_60.sh
#URL:                     https://blog.csdn.net/weixin_40001704
#Description:             The script test
#Copyright(C):            2018 all rights reserved
#**************************************************************
read -p "Are you rich ? (Yes or No):  " answer
if [[ "$answer" =~ ^[Yy]([Ee][Ss])?$ ]];then
        echo OK! You are win!
elif [[ "$answer" =~ ^[Nn][Oo]?$ ]];then
        read -p "Are you handsome ? (Yes or No): " answer
        if [[ "$answer" =~ ^[Yy]([Ee][Ss])?$ ]];then
                echo OK! Toy boy~U are win!
                exit
        elif [[ "$answer" =~ ^[Nn][Oo]?$ ]];then
                echo Work Hard! SaoNian!
        else
                echo "Please input Yes or No"
        fi
else
        echo Please input Yes or No!
fi