shell案例

2019-04-04
#Linux #Shell

  1. 获取随机字符串

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    shelldate +%s%N | md5sum | head -c 8

  1. 批量创建用户

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    #!/bin/bash

    DATE=$(date +%F_%T)
    USER_FILE=user.txt

    if [ -f USER_FILE ];then
            mv $USER_FILE ${USER_FILE}-${DATE}.bak
    fi

    for user in user{10..20};do
            id $user &>/dev/null
            if [ $? -eq 1 ];then
                    useradd $user
                    password=`echo $RANDOM |md5sum | head -c 8`
            echo $password passwd --stdin $user &>/dev/null
            echo -e "$user\tpassowrd" >>$USER_FILE
            echo "add user success"
        else
            echo "user already exist!!!!"
        fi
    done

  1. 检测主机是否存活

    ping 3次,如果不通就是主机down掉了。

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    #!/bin/bash
    for ip in 192.168.1.{1..254};do
    	timeout 1 ping  $ip -c3 -i0.02
    	if [ $? -eq 1 ];then
    		echo "$ip is down"
    	fi
    done

  1. 监控cpu,内存和硬盘利用率

  2. 检查网站可用性