Essential Linux Commands, Directory Structure, and Vim Shortcuts

Linux Directory Structure

Linux, the most widely deployed server operating system, is based on Unix, open‑source and free, offering stability and security. Its directory hierarchy is organized as follows:

bin – binary executables

sbin – system binaries (root only)

etc – system configuration files

usr – shared system resources

home – user home directories

root – superuser home

dev – device files

lib – shared libraries and kernel modules

mnt – mount points for temporary filesystems

boot – boot loader files

tmp – temporary files

var – variable data files

Common Linux Commands

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

ls -la /usr

2.1 File and Directory Operations

Illustrated examples show how to list, copy, move, and delete files and directories.

2.2 System Commands

Typical system utilities such as ps, top, df, and free are presented with screenshots.

2.3 Compression and Decompression

Commands for creating and extracting archives (e.g., tar, gzip, unzip) are demonstrated.

2.4 File Permission Operations

Linux file permissions are described using symbolic (r, w, x) and numeric (e.g., 764) notation. The permission string consists of:

First character: file type (d for directory, - for regular file, l for link)

Next three characters: user permissions (u)

Following three: group permissions (g)

Last three: other permissions (o)

‘a’ can be used to represent all permissions.

Linux Keyboard Shortcuts and Symbols

A collection of frequently used shortcut keys and symbolic commands is provided.

Vim Editor

Vim is the most common text editor on Linux, operating entirely via commands. The article shows the mode‑switching diagram and covers:

4.1 Editing Text

Basic insert, delete, and replace operations with visual examples.

4.2 Navigation Commands

Key combinations for moving the cursor, searching, and jumping between files.

4.3 Replace and Undo Commands

How to substitute text and revert changes.

4.4 Delete Commands

Various ways to delete characters, lines, and blocks.

4.5 Common Shortcuts

A summary of essential Vim shortcuts for efficient editing.