1. 优雅地使用命令行：Tmux 终端复用
2. Tmux入门教程
3. 玩转 vim 与 Terminal (视频)
4. vim + tmux - OMG!Code
5. Basic tmux Tutorial - Windows, Panes, and Sessions over SSH
6. Raspberry Pi 4 Cooling
7. Getting Started With The Raspberry Pi 4 - Use It As A Linux PC

8. Why crontab scripts are not working?: crontab tricks

   1. restart cron in redhat: sudo /etc/init.d/crond restart (sudo service crond restart does not work)
   2. add #!/bin/bash at the top to make sure run in bash
   3. PATH
   4. crontab file should end with an empty line
   5. change file to executable as 755

To test if an cron job works or not, put the following code in the .sh cron file and then wait for the execution result:

 * * * * * env > /home/songjack/cron/env.from.cron.output