Getting Started with UNIX
UNIX is built around a simple yet powerful design philosophy: “Everything is a file.” This allows UNIX to be highly adaptable across different computing environments.
Basic UNIX Commands
| Command | Description |
|---|---|
| ls | Lists files in a directory |
| cd | Changes directory |
| mkdir | Creates a new directory |
| rm | Deletes a file or directory |
| cp | Copies files |
| mv | Moves or renames files |
| chmod | Changes file permissions |
| grep | Searches text within files |
| ps | Displays active processes |
| kill | Terminates a process |
UNIX File System & Navigation
The UNIX file structure is hierarchical, starting from the root directory /. Learn how to navigate and manage files efficiently.
Key Directories in UNIX:
/- Root directory/bin- Essential user binaries/etc- System configuration files/home- User home directories/var- Variable data (logs, databases)/usr- User-related programs and libraries
Editing Text Files
UNIX provides several powerful tools to edit text files directly from the terminal. Here are the most commonly used editors:
1. nano (Beginner-Friendly)
nano is a straightforward text editor ideal for beginners. It displays commands at the bottom of the screen and is easy to use.
Example: nano myfile.txt
Use Ctrl + O to save and Ctrl + X to exit.
2. vi or vim (Advanced)
vi is a powerful editor built into most UNIX systems. vim is an improved version with extended features. These editors have two modes: normal mode and insert mode.
Example: vi myfile.txt
i– Enter insert modeEsc– Return to command mode:w– Save changes:q– Quit:wq– Save and quit
3. cat and echo (Quick Edits)
For very small edits, cat and echo can be used to create or append to files directly.
Create a file: echo "Hello, UNIX!" > hello.txt
Append to a file: echo "Another line" >> hello.txt
View a file: cat hello.txt
Each tool has its strengths — start with nano and gradually explore vim as you become more comfortable with UNIX.