Essential Linux Commands, Directory Structure, and Vim Shortcuts

Linux Directory Structure

bin – stores binary executable files

sbin – stores super‑user binaries (root‑only executables)

etc – contains system configuration files

usr – holds shared system resources

home – root of users' home directories

root – home directory of the super‑user

dev – contains device files

lib – stores shared libraries and kernel modules needed at runtime

mnt – mount points for temporary file systems

boot – files required for system boot

tmp – temporary files

var – variable data files used while the system is running

Common Linux Commands

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

ls -la /usr

File and Directory Operations

System Utilities

Compression and Decompression

File Permission Management

Permission string example drwxr-xr-x is interpreted as:

First character: file type (d = directory, – = regular file, l = symlink)

Next three characters: owner permissions (r = read, w = write, x = execute)

Following three: group permissions (r, w, x)

Last three: permissions for others (r, w, x)

Symbolic letters: r = read, w = write, x = execute; the same permissions can be expressed numerically (111 110 100 → 764).

1st position after the type: user permissions, denoted by u

2nd position after the type: group permissions, denoted by g

3rd position after the type: other permissions, denoted by o

All permissions together can be addressed with a (all)

Linux Shortcuts and Symbolic Commands

Vim Editor

Vim is the most widely used text editor on Linux and operates entirely via command‑mode input without graphical menus.

Editing Text

Navigation Commands

Replace and Undo Commands

Delete Commands

Common Vim Shortcuts