日常脚本分享（持续更新中...）

centos7/8系统初始化脚本(懒人福音)

#! /bin/bash

VERSION_ID=$(grep -oP 'VERSION_ID="\K\d+' /etc/os-release)
DIR=/etc/yum.repos.d
file_path=/etc/chrony.conf


update_yum() {
    cd $DIR && rm -rf * && yum clean all
    if [ "$VERSION_ID" -eq 7 ]; then
        curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo
    else
        curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
    fi
    echo "阿里云yum源配置成功！！！" && sleep 2s
}

# 关闭防火墙和SELINUX
firewalld() {
    systemctl stop firewalld && systemctl disable firewalld &> /dev/null
    sed -i 's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
    echo "SElinux已禁用,重新启动后才可生效" && sleep 2s
}

# 修改主机名称
set_ps1() {
    echo "PS1='\[\e[35m\][\u@\h \W]#\[\e[m\] '" >> /root/.bashrc
    echo "提示符已修改成功,请重新登录生效" && sleep 2s
}


#设置时间同步，为确保某些机器无法通过正常修改时区实现时间同步所以这里直接修改配置文件

datetime() {
    if [ -e "$file_path" ]; then
        echo "chrony服务已经安装，正在配置"
    else
        yum -y install chrony &> /dev/null
        echo "chrony 已成功安装" && sleep 2s
    fi
    cat <<EOF > /etc/chrony.conf
# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html)
# 国家服务器
server 0.cn.pool.ntp.org
server 1.cn.pool.ntp.org
server 2.cn.pool.ntp.org
server 3.cn.pool.ntp.org
# 阿里
server ntp.aliyun.com
# 腾讯
server time1.cloud.tencent.com
server time2.cloud.tencent.com
server time3.cloud.tencent.com
server time4.cloud.tencent.com
server time5.cloud.tencent.com
# if its offset is larger than 1 second.
makestep 1.0 3
# Enable kernel synchronization of the real-time clock (RTC).
rtcsync
# Specify directory for log files.
logdir /var/log/chrony 
EOF
    timedatectl set-timezone Asia/Shanghai && systemctl restart chronyd
    echo "时间同步已同步完成" && sleep 2s
}

# 修改epel源
update_epel() {
    yum clean all &> /dev/null
    sudo sed -e 's!^metalink=!#metalink=!g' \
    -e 's!^#baseurl=!baseurl=!g' \
    -e 's!https\?://download\.fedoraproject\.org/pub/epel!https://mirrors.tuna.tsinghua.edu.cn/epel!g' \
    -e 's!https\?://download\.example/pub/epel!https://mirrors.tuna.tsinghua.edu.cn/epel!g' \
    -i /etc/yum.repos.d/epel*.repo
    echo "epel源配置完毕" && sleep 2s
}

yum_epel() {
    if [ -e /etc/yum.repos.d/epel*.repo ]; then
        update_epel
    else
        yum remove -y epel-release &> /dev/null && yum -y install epel-release &> /dev/null
        update_epel
    fi
}

# 安装一些常用软件
yum_install(){
    yum update &> /dev/null
    echo "正在安装常用软件..."
    yum -y install vim wget tree net-tools lrzsz zip lsof tcpdump  &> /dev/null
    echo "常用软件安装完成，所有配置已就绪，系统将在5秒后重启..." && sleep 5s && reboot
}

start(){
    update_yum
    firewalld
    set_ps1
    datetime
    yum_epel
    yum_install
}

start

生产案例：将指定目录下的文件所有文件的后缀改名为bak后缀

#！/bin/bash
DIR=/data/test
cd $DIR || {    echo 无法进入   $DIR;exit 1; }
for FILE in * ;do
    PRE=`echo $FILE | grep -Eo ".*\."`
    mv $FILE ${PRE}bak
    PRE=`echo $FILE|rev|cut -d. -f 2-|rev`
    PRE=`echo $FILE | sed -nr 's/(.*)\.([^.]+)$/\1/p'`
    SUFFIX=`echo $FILE | sed -nr 's/(.*)\.([^.]+)$/\2/p'`
    mv $FILE $PRE.bak
done

批量创建用户并设置随机密码

#！/bin/bash
for i in {1..10};do
    useradd user$i
    PASS=`cat /dev/urandom | tr -dc '[:alnum:]' | head -c12`
    echo $pass | passwd --stdin user$i &> /dev/null
    echo user$i:$PASS >> /data/user.log
    echo "user$i is created"
done