Linux cd command is a command used to change directory in Linux command line terminal. The command just did that. There is no option available for the cd command. Changing directory in Linux is common. So you are going to use Linux cd command a lot when you are working in the Linux command line terminal.

You need to check your hard disk partitions from time to time to keep your eyes on hard disk usage and to make sure your hard disk is not out of space. Normally, the /home partition always running out of space if you setup Linux as a desktop. It's because you are using a normal user account to do your job and keep all data in /home/ directory. If you setup your Linux as a server, then give most of your hard disk space to the main partition (the mount point).

'cp' is a Linux command used to copy files and directories in Linux command line terminal. To copy file means to duplicate a file or make an extra copy of a file. The Linux cp command is quite important and used frequently when we work in the command line terminal. Normally, we use Linux cp command to backup a file. A situation example is when we are going to edit an important file such as a server configuration file. We can either copy one file to a given destination, or copy many files to a destination directory.

Linux ls command is used to list directory content in Linux command line terminal. In other words, the Linux ls command can be used to view the content of a directory in Linux system. If you are familiar with windows command prompt, or dos, then the equivalent command to the Linux ls is the dir command.

Here is a part of the Linux ls command manual page:

There is a secure copy command in Linux that you can use to copy file or directory from remote computer. This is definitely a good option if you are going to transfer data remotely and need an encryption. The command we are talking about is the Linux scp command. We can run scp command from any Linux distribution's command line terminal.

As a Linux user, you must be able to manage user account in the Linux system. You need to know how to edit or modify a Linux user account information, such as change user password, assign groups to user account, remove group from the user account, change user login name, change password and many more. There is one command in Linux that can do all those stuff. That command is usermod command.

In Ubuntu, you can also surf the Internet or view website in command line terminal. The great browser for command line terminal is Lynx. Lynx package is not install by default. Installing lynx package in Ubuntu is very easy using apt package management system if you already have an Internet connection.

Here is an example on how to install lynx with apt-get:

Linux bash history keeps every command a user typed in the command line terminal into a file named .history. What good about this is that user can re-used the command in case they are lazy to type a very long argument presented with the command. It also faster to use bash command history rather than typing the same command all over again. That makes working in Linux command line virtual terminal a bit fun.

Here is a description from the bash history manual page:

Linux environment variables are settings for user's terminal environment, such as system path, application setting, and default shell. Setting Linux environment is like setting your workplace. It can greatly improve your work. You can customize Linux environment and set almost everything in your Linux system to be the way you want.

Although many Linux distributions nowadays offer great and powerful graphical user interface window (GUI) tools, Linux commands still proved to be very useful and efficient in certain circumstances. Not to mention, working in Linux terminal is fun, fast and a great way at learning Linux operating system.