2. Navigating the file system

What you will learn in this chapter:

• pwd / ls / cd — where am I, what's here, where do I go?
• mkdir / touch — creating directories and files
• cp / mv / rm — copying, moving, deleting
• The difference between absolute and relative paths (/etc/hosts vs ../config)
• Hidden files (those starting with .) and glob patterns

⏱ Time: ~25 minutes 🧪 Exercises: bashlings watch — 8 interactive exercises ready (exercises/02_navigation/)

The Linux/Unix file system is one big tree. Its root is represented by the / symbol. Everything lives under this root: user files, programs, devices, and even system settings.

/
├── bin/      # core executable files (ls, cat, ...)
├── etc/      # configuration files
├── home/     # user directory (Linux)
├── Users/    # user directory (macOS)
├── tmp/      # temporary files
├── usr/      # additional programs and libraries
└── var/      # logs, mail, and variable data

2.1. pwd — where am I?

pwd (Print Working Directory) — shows the full path of the directory you are currently in.

$ pwd
/Users/mac/Desktop/projects

Absolute and Relative paths

• Absolute path — starts from /: /Users/mac/Documents
• Relative path — relative to the current directory: ./docs or ../images

2.2. ls — files in a directory

ls (list) — lists the files in the current or a specified directory.

ls                    # simple listing
ls -l                 # detailed (long format)
ls -a                 # including hidden files (.)
ls -lh                # human-readable size (KB, MB)
ls -la                # the most commonly used combination
ls -lt                # ordered by time
ls -lS                # ordered by size
ls /etc               # contents of another directory
ls *.md               # only .md files

Output of ls -l:

-rw-r--r--  1 mac  staff   2.1K Mar 14 10:22 README.md
drwxr-xr-x  4 mac  staff   128B Mar 12 09:00 src

Each column:

Column	Meaning
-rw-r--r--	Permissions
1	Number of hard links
mac	Owner
staff	Group
2.1K	Size
Mar 14 10:22	Modification time
README.md	File name

Permission symbols

• - — regular file, d — directory, l — symlink
• r — read, w — write, x — execute
• Order: owner / group / others

2.3. cd — change directory

cd (Change Directory):

cd /etc                # by absolute path
cd Documents           # to Documents inside the current directory
cd ..                  # one level up
cd ../..               # two levels up
cd ~                   # to the home directory
cd                     # also to the home directory (shortcut)
cd -                   # back to the previous directory
cd /                   # to the root

Shortcuts

Symbol	Meaning
~	Home directory (/Users/mac)
.	Current directory
..	Parent directory
-	Previous directory (with cd -)

2.4. mkdir — create a new directory

mkdir loyiha                       # a single directory
mkdir loyiha tests docs            # multiple directories
mkdir -p src/components/buttons    # nested (parents are created too)
mkdir -v new_folder                # verbose: shows what was done

The -p (parent) flag is very powerful — if directories in the path don't exist, it creates them all:

mkdir -p projects/2026/january/reports
# all 4 levels are created

mkdir errors

Without -p, if a parent directory does not exist, it raises an error:

mkdir: a/b/c: No such file or directory

2.5. touch — create an empty file

touch readme.txt                   # a new empty file
touch file1.txt file2.txt          # multiple files
touch -t 202601011200 old.txt      # create with a set timestamp

An extra job of touch

If the file already exists, touch updates its last modification time (not its contents).

2.6. cp — copy

cp manba.txt nusxa.txt              # copy of a file
cp file.txt /tmp/                    # to another directory
cp -r src/ backup/                   # recursive (for directories)
cp -v a.txt b.txt                    # verbose
cp -i a.txt b.txt                    # interactive (asks before overwriting)
cp -p file.txt copy.txt              # preserve permissions and timestamp
cp *.md docs/                        # all .md files

-r is required

If you want to copy a directory, don't forget the -r (recursive) flag:

cp folder1 folder2          # WRONG
cp -r folder1 folder2       # CORRECT

2.7. mv — move or rename

mv does two jobs: moving files to another location and renaming.

mv eski.txt yangi.txt                # rename
mv file.txt /tmp/                    # move
mv *.log logs/                       # multiple files
mv -i a.txt b.txt                    # interactive
mv -n a.txt b.txt                    # don't overwrite if it exists
mv -v old.txt new.txt                # verbose

Trick

mv doesn't require -r for directories — it always works "fully":

mv src/ archive/   # works correctly

2.8. rm — delete

The most dangerous command!

A file deleted with rm cannot be recovered. It doesn't go to the Trash. It's gone — that's it.

rm fayl.txt              # a single file
rm a.txt b.txt c.txt     # multiple files
rm -i fayl.txt           # asks for confirmation
rm -f fayl.txt           # force, without asking
rm -r katalog/           # recursive (for directories)
rm -rf katalog/          # FORCE + RECURSIVE — be careful!

Dangerous antipatterns

rm -rf /                 # ❌ deletes the entire system
rm -rf $UNDEFINED_VAR/*  # ❌ if the variable is empty = rm -rf /
rm -rf * .git            # ⚠ watch out for the space

Safe practice

1. Instead of rm, use safe-delete utilities like trash or gomi.
2. Before ever using rm -rf with a variable, check it with echo:

echo rm -rf "$PROJECT_DIR"   # first we look
rm -rf "$PROJECT_DIR"        # now we run it

2.9. rmdir — remove an empty directory

rmdir only removes empty directories:

rmdir empty_folder       # removes it if empty
rmdir non_empty          # ERROR: "Directory not empty"

For a non-empty directory, use rm -r.

2.10. tree — tree view

Displays the directory structure visually (you may need to install it separately):

brew install tree    # macOS
sudo apt install tree  # Ubuntu/Debian

tree                  # current directory
tree -L 2             # up to 2 levels
tree -a               # including hidden files
tree -d               # only directories

Output:

.
├── docs/
│   ├── part1/
│   │   ├── 01-introduction.md
│   │   └── 02-navigation.md
│   └── index.md
└── package.json

2.11. Wildcards (Globbing)

Bash supports wildcard (joker) symbols for specifying multiple files:

Symbol	Meaning	Example
*	Any character(s)	*.txt, report-*
?	Exactly one character	file?.txt
[abc]	One of a, b, or c	f[123].log
[a-z]	A range	[a-c]*.md
{a,b}	Brace expansion	{src,test}/*.js

Examples:

ls *.md                       # all .md files
rm temp_?.log                 # temp_1.log, temp_2.log, ...
cp report-{2024,2025}.pdf bk/  # works with both
ls /etc/[a-c]*                # those starting with a, b, or c

2.12. Real example: creating a project skeleton

# 1. Main directory
mkdir -p ~/projects/my-app
cd ~/projects/my-app

# 2. Structure
mkdir -p src/{components,utils,services} tests docs

# 3. Empty files
touch README.md .gitignore package.json
touch src/index.js src/utils/helpers.js

# 4. Let's check
tree -L 3

2.13. Exercises

🧪 Bashlings — interactive exercises

This chapter's 8 exercises come with auto-checking via the bashlings CLI:

bashlings watch              # start from the first pending exercise
bashlings run nav1           # check a single exercise
bashlings hint nav1          # step-by-step hint

Source: exercises/02_navigation/

Do the following additional tasks by hand in the terminal:

1. In your home directory, create a directory named bash-mashq and, inside it, create the subdirectories notes, scripts, and archive with a single command.
2. Inside scripts/, create the files hello.sh, backup.sh, and cleanup.sh.
3. Make a copy of hello.sh named hello.bak in the same directory.
4. Delete the archive directory.
5. Move all .sh files into the notes/ directory with a single command.

2.14. Summary

Command	Purpose
pwd	Show the current directory
ls	View the contents of a directory
cd	Change directory
mkdir	Create a new directory
touch	Create a new empty file
cp	Copy
mv	Move or rename
rm	Delete (with care!)
rmdir	Remove an empty directory
tree	Display in a tree view

Now you have the skill to move freely around the file system. In the next chapter we will learn to connect commands through I/O redirection and pipelines.

Next page: 3. I/O Redirection and Pipelines →