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01 Getting Started

01.01 Getting Started: What is Linux and Linux Distributions (distro)

What is an Operating System?

• When you turn your device on, it boots up the operating system, which The main software on a system. It manages the communication/interface between your applications and the hardware it is running on.
  

  Image Added

  As shown in the image above, an operating system (OS) functions between the computer’s hardware and the applications that run on the computer.

What is Linux?

• Linux is an Operating Systems – similar to Windows, Mac OS, iOS, Android.

• Linux is open-source – freely available – so you can download, modify and redistribute.

• Due to this there are 10s of varieties of Linux Distributions (distros):

  • Debian

    • Ubuntu (based on Debian)

  • Fedora

    • Amazon Linux 2

  • Commercial: Red Hat (which we are using today)

    • Rocky Linux

• There is a lot of commonality across these distros.

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• Desktop: Windows type Graphical User Interface (GUI)  - mouse point and click.

• Terminal: Program that opens a graphical window and runs a:

  • Shell which is a command interpreter that processes the typed commands.

    • Interface to the OS.

    • Provides a Command-Line Interface (CLI) – text-based input/output.

    • Different Shells share common commands, but syntax and behavior can be different.

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02 Using the Terminal

• What does a prompt look like?

• General syntax of shell command.

• Commands/options are case sensitive.

• Getting Help:

  • Man pages (man)

  • Options: <command> --help

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• Steps through the previous commands you’ve typed.

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03 File System

• What the file system is, and a typical organization / hierarchy.

• Some high-level comparison to that of Windows.

• Absolute vs relative paths.

• Commands: pwd, cd, ls, mv, cp, mkdir, rmdir, rm

• History: history

• File Ownership and Permissions.

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# Can you cd into the /opt folder?
[arcc-t05@blog1 ~]$ cd /opt
[arcc-t05@blog1 opt]$

# Can you cd into the /root folder?
[arcc-t05@blog1 ~]$ cd /root
-bash: cd: /root: Permission denied

# Justify your answer.
[arcc-t05@blog1 ~]$ ls -l /
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# “other” has read permissions
drwxr-xr-x.    5 root root    43 Jun 26 11:47 opt
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# No permission set for other read permissions
dr-xr-x---.   17 root root  4096 Oct  4 12:58 root

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04 Next Steps, Summary

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04.01 Next Steps, Suggestions

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