Master Linux Basics: Directory Structure, Common Commands, and Vim Essentials

Linux Overview

Linux is the most widely used server operating system, built on Unix, open‑source and free, offering high stability and security; it runs on servers, smartphones, routers and many other hardware platforms.

1. Linux Directory Structure

The root (/) directory contains the following standard sub‑directories:

bin : binary executable programs for all users.

sbin : system binaries, typically used by the root user.

etc : system configuration files.

usr : shared read‑only data, libraries, and application files.

home : personal home directories of regular users.

root : home directory of the superuser.

dev : device files representing hardware.

lib : shared libraries and kernel modules required by programs.

mnt : mount points for temporarily attached file systems.

boot : files needed for system booting.

tmp : temporary files.

var : variable data such as logs, caches and spool files.

2. Common Linux Commands

Command format: command -options arguments (options and arguments may be omitted).

Example: ls -la /usr

2.1 File and Directory Operations

Typical commands for creating, moving, copying and deleting files and directories are illustrated in the accompanying diagrams.

2.2 System Commands

Commands for viewing system status, managing processes, and checking resource usage are shown.

2.3 Compression and Decompression

Common tools such as tar, gzip, zip and their usage examples are presented.

2.4 File Permission Operations

Linux file permissions are expressed with symbolic letters or octal numbers. The symbolic format consists of three groups (user, group, other) and three permission bits (read r, write w, execute x). An example numeric representation is 764 (rwx for owner, rw‑ for group, r‑‑ for others). The first character indicates the file type (d for directory, - for regular file, l for symbolic link). The full permission string can also be addressed with shortcuts: u (user), g (group), o (other), a (all).

r – read permission

w – write permission

x – execute permission (or access for directories)

First character: file type (d, -, l)

Next three characters: owner permissions (u)

Following three: group permissions (g)

Last three: other permissions (o)

3. Linux Shortcuts and Symbolic Commands

Common keyboard shortcuts and symbolic command aliases that speed up shell navigation are listed and illustrated.

4. Vim Editor

Vim (or vi) is the most powerful text editor on Linux, operating in modal fashion without graphical menus. The following sections summarize its most frequently used commands, each accompanied by a diagram.

4.1 Editing Text

Basic insert, delete, and change commands.

4.2 Navigation Commands

Commands for moving the cursor, searching, and jumping between lines.

4.3 Replace and Undo Commands

4.4 Delete Commands

4.5 Common Shortcuts