Navigating the File System

The Linux File System

Everything in Linux is organized in a tree structure starting from the root directory /. Understanding this hierarchy is essential for DevOps work.

Key Directories

/
├── home/       # User home directories
├── etc/        # System configuration files
├── var/        # Variable data (logs, databases)
├── usr/        # User programs and utilities
├── tmp/        # Temporary files
├── opt/        # Optional/third-party software
├── bin/        # Essential command binaries
├── sbin/       # System administration binaries
└── dev/        # Device files

pwd — Print Working Directory

# Shows your current location
pwd
# Output: /home/username

ls — List Directory Contents

# Basic listing
ls
 
# Detailed listing with permissions
ls -l
 
# Show hidden files
ls -a
 
# Combine flags
ls -la
 
# Human-readable file sizes
ls -lh

cd — Change Directory

# Go to home directory
cd ~
cd
 
# Go to root
cd /
 
# Go up one level
cd ..
 
# Go to previous directory
cd -
 
# Navigate to a specific path
cd /var/log

Paths

Absolute Paths

Start from root /:

cd /home/username/documents
cd /etc/nginx/conf.d

Relative Paths

Start from current directory:

# If you're in /home/username
cd documents        # Goes to /home/username/documents
cd ../otheruser     # Goes to /home/otheruser
cd ./projects       # Goes to /home/username/projects

Useful Shortcuts

Shortcut	Description
`~`	Home directory
`.`	Current directory
`..`	Parent directory
`-`	Previous directory
Tab	Auto-complete
Tab Tab	Show all options

Practice Exercises

Try these commands in sequence:

# 1. Check where you are
pwd
 
# 2. Go to the root directory
cd /
 
# 3. List all top-level directories
ls -l
 
# 4. Navigate to /var/log
cd /var/log
 
# 5. List log files
ls -la
 
# 6. Go back home
cd ~
 
# 7. Create a practice directory
mkdir -p devops-practice/linux
 
# 8. Navigate into it
cd devops-practice/linux
 
# 9. Confirm your location
pwd

Summary

You now know how to:

Understand the Linux file system hierarchy
Navigate using cd, ls, and pwd
Work with absolute and relative paths
Use shortcuts for faster navigation

Next Steps

Next, we'll learn about file operations — creating, copying, moving, and deleting files and directories.

Learning Objectives