1、编写脚本/bin/per.sh,判断当前用户对指定参数文件，是否不可读并且不可写
#!/bin/bash
read -p "please input a filename:" file
if [ ! -e $file ];then
echo "file is not exits"
elif [ ! -r $file -a ! -w $file ];then
echo "$USER can't read and write $file"
else
echo "$file can read or write"
fi
执行结果：
[[email protected] testdata]# chmod +x per.sh
[[email protected] testdata]# ./per.sh
please input a filename:/etc/shadow
/etc/shadow can read or write
[[email protected] testdata]# su cwj
[[email protected] testdata]$ ./per.sh
please input a filename:/etc/shadow
cwj can't read and write /etc/shadow
2、编写脚本/root/bin/excute.sh ，判断参数文件是否为sh后缀的普通文件，如 果是，添加所有人可执行权限，否则提示用户非脚本文件
#!/bin/bash
read -p "please input a file:" file
if [ -e $file ];then
if [ -f $file ];then
suffix=`echo "$file" | awk -F. '{print $NF}'`
if [ $suffix == "sh" ];then
chmod a+x $file
echo "$file change mode success"
else
echo "$file is not script file"
fi
else
echo "file is not a normal file"
fi
else
echo "file is not exits"
fi
运行结果：
[[email protected] testdata]# ./excute.sh
please input a file:scp1.exp
scp1.exp is not script file
[[email protected] testdata]# ./excute.sh
please input a file:per.sh
per.sh change mode success
3、编写脚本/root/bin/nologin.sh和login.sh,实现禁止和允许普通用户登录系统
禁止用户登录：
#!/bin/bash
read -p "please input user name:" name
id $name >/dev/null
if [ $? -eq 0 ];then
userid=`id $name |sed -r 's/.*=([0-9]+).*/\1/'`
if [ $userid -ge 500 ];then
usermod -s /sbin/nologin $name
echo "usermod success"
else
echo "$name is a system user"
fi
else
echo "$name is not exits"
fi
运行结果：
please input user name:cwj
usermod success
[[email protected] testdata]# ./nologin.sh
please input user name:root
root is a system user
[[email protected] testdata]# getent passwd cwj
cwj:x:1000:1000:cwj:/home/cwj:/sbin/nologin
允许用户登录：
#!/bin/bash
read -p "please input user name:" name
id $name >/dev/null
if [ $? -eq 0 ];then
userid=`id $name |sed -r 's/.*=([0-9]+).*/\1/'`
if [ $userid -ge 500 ];then
usermod -s /bin/bash $name
echo "usermod success"
else
echo "$name is a system user"
fi
else
echo "$name is not exits"
fi
运行结果：
[[email protected] testdata]# chmod +x login.sh
[[email protected] testdata]# ./login.sh
please input user name:cwj
usermod success
[[email protected] testdata]# ./login.sh
please input user name:root
root is a system user
[[email protected] testdata]# getent passwd cwj
cwj:x:1000:1000:cwj:/home/cwj:/bin/bash
4、编写脚本/root/bin/sumid.sh，计算/etc/passwd文件中的第10个用户和第 20用户的ID之和
#! /bin/bash
user10="`head -n $2 $1 | tail -n 1|cut -d: -f3`"
user20="`head -n $3 $1 | tail -n 1|cut -d: -f3`"
let sum=$user10+$user20
echo "user id sum is $sum"
5、用两种以上方式查目的地当前服务器上面io最繁忙的是哪块硬盘
- top命令
- 使用iostat，可以非常详细的查看到是哪块硬盘最繁忙,iostate 默认不安装在系统中，需要使用Yum安装： yum install iostat
6、在 12 月内, 每天的早上 6 点到 12 点，每隔 3 个小时 0 分钟执行一次 /usr/bin/backup 0 6-12/3 * 12 * /usr/bin/backup
- 编写backup脚本
#!/bin/bash
cp /etc/passwd /home/cwj/testdata/passwd.bak`date +%F-%T`
2、编写计划任务
0 6-12/3 * 12 * /home/cwj/testdata/backup