一、if语句、while、for循环各种小例题
1.用户验证
[[email protected] ~]# cat buer.sh
#!/bin/bash
#user=‘buer‘
#password=‘1234.com‘
read -p ‘please your name:‘ user
read -p ‘password:‘ passwd
if [ $user = ‘buer‘ -a $passwd = ‘1234.com‘ ];then
echo ‘login successful‘
fi
2.猜年龄
#!/bin/bash
age=57
read -p ‘num:‘ num
if [ $num -eq $age ];then
echo ‘you get it‘
elif [ $num -gt $age ];then
echo ‘too big‘
elif [ $num -lt $age ];then
echo ‘too samll‘
fi
3.查询成绩
[[email protected] ~]# cat score.sh
#!/bin/bash
read -p ‘please your score:‘ score
if [ $score -ge 90 ];then
echo ‘very good!‘
elif [ $score -ge 70 -a $score -lt 90 ];then
echo ‘good!‘
elif [ $score -ge 60 -a $score -lt 70 ];then
echo ‘just like‘
else
echo ‘poor‘
fi
4.for循环打印1235
[[email protected] ~]# cat for.sh
#!/bin/bash
for i in {1..5}
do
if ((i == 4));then
continue
#break
fi
echo ‘=======‘ $i
done
脚本4的执行结果：
[[email protected] ~]# ./for.sh ======= 1 ======= 2 ======= 3 ======= 5
5.改进版的猜年龄
[[email protected] ~]# cat oldboy.sh
oldboy=57
while :
do
read -p ‘input your age:‘ age
if [ -z $age ];then
continue
fi
if [ $age -eq $oldboy ];then
echo "bingo"
break
elif [ $age -lt $oldboy ];then
echo "little"
elif [ $age -gt $oldboy ];then
echo "big"
else
echo "bye"
fi
done
脚本5结果：
[[email protected] ~]# ./oldboy.sh input your age:45 too samll input your age:65 too big input your age:57 you get it [[email protected] ~]#
6.查看文件类型
[[email protected] ~]# cat aa.sh
#!/bin/bash
while :
do
read -p ‘input your file:‘ file
if [ -z $file ];then
continue
elif [ $file = ‘quit‘ ];then
break
fi
if [ -b $file ];then
echo "$file is block file"
elif [ -d $file ];then
echo "$file is directory file"
elif [ -f $file ];then
echo "$file is regular file"
else
echo "$file unkown"
fi
done
脚本6结果：
[[email protected] ~]# sh aa.sh input your file:/etc /etc is directory file input your file:/pm /pm unkown input your file:quit
7.打印乘法口诀表
[[email protected] ~]# cat cheng.sh
#!/bin/bash
for ((i=1;i<=9;i++))
do
for ((j=1;j<=i;j++))
do
echo -n "$i*$j=$[$i*$j]"
done
echo
done
脚本7结果：
[[email protected] ~]# ./cheng.sh 1*1=1 2*1=22*2=4 3*1=33*2=63*3=9 4*1=44*2=84*3=124*4=16 5*1=55*2=105*3=155*4=205*5=25 6*1=66*2=126*3=186*4=246*5=306*6=36 7*1=77*2=147*3=217*4=287*5=357*6=427*7=49 8*1=88*2=168*3=248*4=328*5=408*6=488*7=568*8=64 9*1=99*2=189*3=279*4=369*5=459*6=549*7=639*8=729*9=81
8.批量创建用户
[[email protected] ~]# cat add.sh
#!/bin/bash
for i in {1..5};
do
useradd user$i && echo "user$i create successful"
done
脚本8执行结果：
[[email protected] ~]# sh add.sh user1 create successful user2 create successful user3 create successful user4 create successful user5 create successful
9.批量删除用户
[[email protected] ~]# cat del.sh
#!/bin/bash
for i in {1..5};
do
userdel -r user$i && echo "user$i delete successful"
done
脚本9执行结果：
[[email protected] ~]# sh del.sh user1 delete successful user2 delete successful user3 delete successful user4 delete successful user5 delete successful
10.循环叠加打印数字，并睡眠1s
[[email protected] ~]# cat conut.sh
#!/bin/bash
count=1
while ((count < 10))
do
echo ‘==========>‘ $count
sleep 1
((count+=1))
done
执行结果：
[[email protected] ~]# sh conut.sh ==========> 1 ==========> 2 ==========> 3 ==========> 4 ==========> 5 ==========> 6 ==========> 7 ==========> 8 ==========> 9
11.批量ping ip
[[email protected] ~]# cat ping.sh
#!/bin/bash
for i in {1..100};
do
ping -c1 192.168.16.$i &> /dev/null
if [ $? -eq 0 ];then
echo "192.168.16.$i OK"
echo "192.168.16.$i" >> /tmp/ip.txt
fi
done
12.模仿登录用户小工具
[[email protected] ~]# cat login.sh
#!/bin/bash
user=‘buer‘
passwd=‘1234.com‘
while $tag
do
read -p ‘input your name:‘ name
read -p ‘input your passwd:‘ pas
if [[ $name = $user ]] && [[ $pas = $passwd ]];then
echo ‘login successful‘
while $tag
do
read -p ‘>>:‘ cmd
if [[ $cmd = ‘quit‘ ]];then
tag=false
else
$cmd
fi
done
fi
done
执行结果：
[[email protected] ~]# sh login.sh input your name:buer input your passwd:1234.com login successful >>:ls aa.sh a.txt del.sh oldboy.sh 模板 下载 add.sh buer.sh for.sh ping.sh 视频 音乐 age.sh cheng.sh initial-setup-ks.cfg score.sh 图片 桌面 anaconda-ks.cfg conut.sh login.sh 公共 文档 >>:pwd /root >>:quit [[email protected] ~]#
时间： 2024-10-05 21:21:39