The basics of how to use Linux (如何使用Linux，基础笔记三)

In this blog, we will see some common commands, and some examples will be shown.

1. Some common commands
   1.1. “date”
   e.g.
   After entered “date”, the current time and date are shown.
   1.2. “cal”
   e.g.
   
   When you entered the “cal” command, the calender of current month was shown in default.
   1.3. “df”
   e.g.
   
   The teminal will show the current amount of free space on your disk drives, when you typed the “df”.
   1.4. “free”
   e.g.
   
   Likewise, the amount of free memory will be displayed, when you type the “free” command.
   1.5. “exit”
   If you want to end the current session of terminal emulator, you could type the “exit”.