常用脚本

1、网络状态判断
#!/bin/bash
#
IP=10.0.0.201
ping -c1 -w1 $IP &> /dev/null && echo "$IP is up" || 
            { echo "$IP is unreachable";exit; }
echo "Script is finished"

 

2、磁盘空间判断
#!/bin/bash
WARNING=30
SPACE_USED=`df |grep -E  "^/dev/(sda*|ma*)"|tr -s ' ' %|cut -d% -f5|sort -nr|head -1`
[ "$SPACE_USED" -ge "$WARNING" ] && echo "disk used is $SPACE_USED.willbe full"

3、体重指数测试
#!/bin/bash

read -p "请输入身高（m为单位）：" HIGH
if [[ ! "$HIGH" =~ ^[0-2]\.?[0-9]{,2}$ ]];then
    echo "输入错误身高"
    exit 1
fi

read -p "请输入体重（kg为单位）：" WEIGHT
if [[ ! "$WEIGHT" =~ ^[0-9]{1,3}$ ]];then
    echo "输入错误体重"
    exit 1
fi

BMI=$(echo "$WEIGHT/$HIGH^2"|bc)                                       

if [ $BMI -le 18 ];then
    echo "太瘦了，多吃点"
elif [ $BMI -lt 24 ];then
    echo "正好！"
else
    echo "太胖了"
fi

4、批量创建用户
#!/bin/bash
if [ $# -eq 0 ];then
    echo "Usage: `basename $0` user1 user2 ..."
    exit
fi

while [ "$1" ];do
    if id $1 &> /dev/null;then
        echo $1 is exist
    else
        useradd $1
        echo "$1 is created"
    fi
    shift
done
echo "All user is created" 

5、磁盘监控
#!/bin/bash
#
WARNING=20                                                             
df |sed -nr "/^\/dev\/sd|ma/s#^([^ ]+) .* ( [0-9]+)%.*#\1\2#p"|while read DEVICE USE;do    
    if [ $USE -gt $WARNING ];then
        echo "$DEVICE will be full,use:$USE"
    fi
done

6、批量禁用iptables
#!/bin/bash
lastb |sed -nr "/ssh:/s#.* ([0-9.]{1,3}{3}[0-9]{1,3}).*#\1#p" |sort |uniq -c |while read count ip;
do    
    if [ $count -gt 3 ];then
        iptables -A INPUT -s $ip -j REJECT
    fi
done 

7、查看/sbin/nologin的shell类型的用户名和UID
#!/bin/bash

while read line
do
    if [[ "$line" =~ /sbin/nologin$ ]];then
        echo $line | cut -d: -f1,3
    fi
done < /etc/passwd

8、自动安装apache
#!/bin/bash

PACKAGE=httpd-2.4.43.tar.bz2
PACKAGRDIR=/usr/local/src
INSTALLDIR=/apps/httpd
CONFDIR=/etc/httpd

yum install -y gcc make apr-devel apr-util-devel pcre-devel mod_ssl openssl-devel
id apache &> /dev/null || useradd -r -s /sbin/nologin apache

cd $PACKAGRDIR
tar xfv $PACKAGE
cd $PACKAGRDIR/httpd-2.4.43
./configure --prefix=$INSTALLDIR --sysconfdir=$CONFDIR --enable-ssl
make -j 4 && make install
echo 'PATH=/apps/httpd/bin:$PATH' > /etc/profile.d/httpd.sh
source /etc/profile.d/httpd.sh

sed -i.bak '/^User/s/daemon/apache/g' /etc/httpd/httpd.conf
sed -i.bak '/^Group/s/daemon/apache/g' /etc/httpd/httpd.conf
apachectl start

9、系统初始化脚本
#!/bin/bash

function disable_selinux {
    sed -i.bak 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
    echo "SElinux已禁用，重新启动后生效"
}

function disable_firewalld {
    systemctl disable --now firewalld &> /dev/null
    echo "防火墙已经禁用"
}

function set_ps1 {
    echo "PS1='\[\e[1;35m\][\u@\h \w]\\$\[\e[0m\]'" > /etc/profile.d/reset.sh
    echo "提示符已修改成功，请重新登录"
}

function set_eth {
    sed -i.bak '/GRUB_CMDLINE_LINUX=/s#"$# net.ifnames=0"#' /etc/default/grub
    grub2-mkconfig -o /boot/grub2/grub.cfg &> /dev/null
    echo "网络名称已修改成功，请重新启动才能生效"
}
PS3="系统初始化（1-6）："
MENU='禁用SELinux 关防火墙 修改提示符 修改网卡名 以上全部 退出'
select M in $MENU;do
case $REPLY in
1)
    disable_selinux
    ;;
2)
    disable_firewalld
    ;;
3)
    set_ps1
    ;;
4)
    set_eth
    ;;
5)
    disable_selinux
    disable_firewalld
    set_ps1
    set_eth
    ;;
6)
    break
    ;;
*)
    echo "请输入正确数字"   
esac
done

10、函数调用
#!/bin/bash
. /etc/init.d/functions    #系统函数调用action显示美观化
function disable_selinux {
    sed -i.bak 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
    action "SElinux已禁用，重新启动后生效"
}

function disable_firewalld {
    systemctl disable --now firewalld &> /dev/null
    action "防火墙已经禁用"
}

function set_ps1 {
    echo "PS1='\[\e[1;35m\][\u@\h \w]\\$\[\e[0m\]'" > /etc/profile.d/reset.sh
    action "提示符已修改成功，请重新登录"
}

function set_eth {
    sed -i.bak '/GRUB_CMDLINE_LINUX=/s#"$# net.ifnames=0"#' /etc/default/grub
    grub2-mkconfig -o /boot/grub2/grub.cfg &> /dev/null
    action "网络名称已修改成功，请重新启动才能生效"
}
PS3="系统初始化（1-6）："
MENU='禁用SELinux 关防火墙 修改提示符 修改网卡名 以上全部 退出'
select M in $MENU;do
case $REPLY in
1)
    disable_selinux
    ;;
2)
    disable_firewalld
    ;;
3)
    set_ps1
    ;;
4)
    set_eth
    ;;
5)
    disable_selinux
    disable_firewalld
    set_ps1
    set_eth
    ;;
6)
    break
    ;;
*)
    echo "请输入正确数字"   
esac
done