shell-第四天作业

1、ping主机测试,查看主机是否存活；

[[email protected] zuoye]# vim 1.sh
#!/bin/bash
ping -c2 192.168.40.128 &>/dev/null
if [ $? -eq 0 ];then
 echo "is runing"
else
 echo "not runing"
fi
~   

2、判断一个用户是否存在；

[[email protected] zuoye]# vim 2.sh
#!/bin/bash
read -p "input user name:" name
id $name &>/dev/null
if [ $? -eq 0 ];then
  echo "$name is exist "
else
  echo "$name is not exist"
fi
~   

3、判断当前内核主版本是否为3，且次版本是否大于10；

[[email protected] zuoye]# vim 3.sh
#!/bin/bash
main="`uname -r |cut -d . -f1`"
sub="`uname -r |cut -d . -f2`"
if [ $main -eq 3 ];then
  if [ "$sub" -gt 10 ];then
    echo "main is 3 and sub more than 10"
  else
    echo "main is 3 but sub less than 10"
  fi
else
  echo "main is not 3"
fi

4、判断vsftpd软件包是否安装，如果没有则自动安装；

[[email protected] zuoye]# vim 4.4.sh
#!/bin/bash
rpm -qa |grep vsftpd
if [ $? -eq 0 ];then
        echo "The vsftpd is install"
else
        yum -y install  vsftpd
        rpm -qa |grep vsftpd

fi

5、判断httpd是否运行；

[[email protected] zuoye]# vim 4.5.sh
#!/bin/bash
systemctl is-active httpd.service &>/dev/null
if [ $? -eq 0 ];then
        echo "httpd is runing "
else
        echo "httpd is not runing"
fi

6、判断指定的主机是否能ping通，必须使用$1变量；

[[email protected] zuoye]# vim 4.6.sh
#!/bin/bash
ping -c2 $1 &>/dev/null
if [ $? -eq 0 ];then
        echo "this ip is up"
else
        echo "this ip is down"
fi

7、报警脚本，要求如下：
根分区剩余空间小于20%
内存已用空间大于80%
向用户alice发送告警邮件
配合crond每5分钟检查一次

[[email protected] zuoye]# vim 4.7.1.sh 
#!/bin/bash
sy=`df -h | grep -w / |awk {'print $5'}|tr -d %`
memory_user=`free -m|grep Mem|awk {'print $3'}`
memory_total=`free -m|grep Mem|awk {'print $2'}`
memory=`echo $memory_user*100/$memory_total|bc`
if [ "$user -gt 80" -o "$memory -gt 80" ];then
       echo "your / use $sy%, your mem use $memory%" |mail -s "warning" root
fi

8、判断用户输入的是否是数字，如果是数字判断该数字是否大于10；

[[email protected] zuoye]# vim 4.8.sh 
#!/bin/bash
read -p "please input anumber :" num
expr 1 + $num
if [ $? -eq 0  ];then
        if [ $num -gt 10 ];then
                echo "Is nmuber and the number more than 10"
        else
                echo "Is number but the number less than 10"
        fi
else
        echo Is not number
fi

9、计算用户输入的任意两个整数的和、差、乘积、商、余数，
判断用户输入的参数是否是两个，如果不是，提示用法；
判断用户输入的是否是整数，如果不是，则给出提示终止运行。

#!/bin/bash
[ $# -ne 2 ] && {
    
 echo "usage: $0 num1 num2"
 exit 1
}
expr $1 + $2 + 10 &> /dev/null
if [ $? -ne 0 ]
then
 echo "you must input two number"
 exit 2
fi
echo "a+b=$(($1+$2))"
echo "a-b=$(($1-$2))"
echo "a*b=$(($1*$2))"
echo "a/b=$(($1/$2))"