# 创建一个空的交换文件 4G
dd if=/dev/zero of=/swapfile bs=1G count=4
dd if=/dev/zero of=/swapfile bs=1M count=4096 # 系统内存不足小块方式创建

chmod 0600 /swapfile # 设置正确的权限
sudo mkswap /swapfile # 设置为交换分区
sudo swapon /swapfile # 挂载

swapon --show # 查看
free -m # 查看

vi /etc/ssh/sshd_config # 编辑配置文件

ClientAliveInterval 60  # 表示每分钟发送一次，然后客户端响应，这样就保持长连接，默认是 0, 不发送.
ClientAliveCountMax 3   # 表示服务器发出请求后客户端没有响应的次数达到一定值，就自动断开.

service sshd restart    # 重启 sshd 服务

# help
https://www.cnblogs.com/adolfmc/p/7248515.html

wget --no-check-certificate -O shadowsocks.sh https://raw.githubusercontent.com/teddysun/shadowsocks_install/master/shadowsocks.sh
chmod +x shadowsocks.sh
./shadowsocks.sh 2>&1 | tee shadowsocks.log

cat /etc/shadowsocks.json       # 查看 config
systemctl restart shadowsocks   # 重启
systemctl status shadowsocks    # 状态

# help
https://github.com/shadowsocks/shadowsocks-windows/releases

####### nginx.conf
user www www;

worker_processes auto;
worker_cpu_affinity auto;

error_log /home/wwwlogs/nginx_error.log crit;

pid /usr/local/nginx/logs/nginx.pid;

var bbk = {
    //问题序号
    qno: 0,
    //答案序号
    ano: 0,
    init: function () {
        bbk.answer();
    },
    /**当前题目序号 */
    currNo: function () {