Command line, shell, console - these terms are used to refer to human interaction with the operating system using standard input-output devices that provide command input and receive the results of their execution. In operating systems of the Linux family, such interaction is provided by a special software product - the shell.
The most common of these is the shell of the GNU bash project.
Before we move on to bash further, we need to understand that a shell (or shell) is a program that accepts and executes programs. The shell also supports programming constructs, allowing you to build complex commands from simpler ones. These complex commands, or scripts, can be saved as files, which can become new standalone commands. Many commands on a typical Linux system are scripts.
The interpreters contain several built-in commands such as cd, break, and exec. Other commands are external.
If you're not using a graphical interface when working on Linux, or if you open a terminal window on a graphical desktop, in both cases you'll get a prompt that might look like this:
For the user
For superuser or root
The root user has unlimited rights, so you should use his account carefully. If you have root user privileges, you will typically see a pound sign (#) at the end of the prompt. If you are running with normal user privileges, the prompt will display a different sign, usually a dollar sign ($). The prompt on your computer may differ from the prompts shown in previous examples in this article. It may contain the username, computer name, current directory, date, time, and so on.
Basic Linux commands 1. ls - A utility for viewing the contents of directories 2. cat - Displaying the contents of a file 3. cd - Allows you to change from the current directory to the specified one. 4. pwd - Show the current directory. 5. mkdir - Create a new directory. 6. cp - Copy files and directories. 8. mv - Move or rename files and directories. 9. rm - Deletes files and folders. 10. chmod - Changes file permissions. 11. chown - Changes the owner of a file. 12. kill / xkill / pkill / killall - Terminate processes. 13. ps - displays information about running processes 14. top - display processes in real time 15. useradd / userdel / usermod - add, remove and modify a user account 16. passwd - change user account password 17. IP - network management utility 18. ping - network diagnostic utility
And in the final, “for dessert”, some more very useful information:
This cheat sheet is very helpful when working with tar archiver syntax (https://files.fosswire.com/2007/08/fwunixref.pdf)
This document contains the main commands: https://csg.sph.umich.edu/docs/Unix_Commands.pdf
Have a nice and easy job!