Basic Linux commands exercises — get comfortable in the terminal
Basic Linux commands exercises are where the terminal stops feeling foreign. You’ve seen the theory and practiced navigating Fedora. Now it’s time to solve challenges on your own, with wildcards, paths, basic permissions and a final challenge that combines everything.
These exercises are done directly in your Fedora terminal. Open it now and keep it open throughout the article.
As always: try to solve it yourself, check the hint if you’re stuck for more than 10 minutes, and compare with the solution at the end.
Table of Contents
Before starting every exercise
pwd # confirm where you are
Getting lost is the most common frustration. Make pwd a reflex.
Basic Linux commands exercises — Basic Level
Exercise 1 — Wildcards and patterns
Wildcards let you work with multiple files at once using pattern matching. The most common are * (any characters) and ? (any single character).
Set up the exercise:
mkdir ~/wildcard_exercise cd ~/wildcard_exercise touch report_2023.txt report_2024.txt report_final.txt touch data_january.csv data_february.csv data_march.csv touch main.c utils.c header.h touch notes.txt backup.txt readme.md ls
Now solve these tasks using wildcards, don’t type each filename individually:
Task A: List only the .txt files
Task B: List only the .c files
Task C: List all files that start with report
Task D: List all files that contain data
Task E: Create a folder called csv_files and move all .csv files into it
Task F: Create a folder called c_source and copy all .c and .h files into it
Task G: Delete all files that start with backup
💡 Hints:
*.txt # any filename ending in .txt *.c # any filename ending in .c report* # any filename starting with report *data* # any filename containing data ls *.txt # list all .txt files mv *.csv folder/ # move all .csv files
Exercise 2 — Paths and navigation challenge
The goal: navigate and create files using both absolute and relative paths, without using the graphical file manager.
Set up:
mkdir -p ~/path_exercise/ProjectA/src mkdir -p ~/path_exercise/ProjectA/docs mkdir -p ~/path_exercise/ProjectB/src mkdir -p ~/path_exercise/shared cd ~/path_exercise
Solve these tasks:
Task A: From ~/path_exercise, create a file called main.c inside ProjectA/src using a relative path
Task B: From ProjectA/src, create a file called utils.c in ProjectB/src using a relative path (hint: ../../)
Task C: From anywhere on the system, copy main.c from ProjectA/src to shared/ using absolute paths
Task D: From ProjectB/src, list the contents of ProjectA/docs using a relative path
Task E: From ~/path_exercise/ProjectA/src, go to ~/path_exercise/shared using only cd with relative paths (no absolute paths, no cd ~)
💡 Hints:
# From ~/path_exercise touch ProjectA/src/main.c # relative path # From ProjectA/src, to ProjectB/src touch ../../ProjectB/src/utils.c # go up twice, then down # Absolute path always starts with / cp /home/sergio/path_exercise/ProjectA/src/main.c /home/sergio/path_exercise/shared/ # Relative path from ProjectA/src to shared ls ../../shared/
Basic Linux commands exercises — Intermediate Level
Exercise 3 — File organisation and search
A realistic scenario: you’ve just finished a semester and your files are completely disorganised. Your task is to organise them using only terminal commands.
Set up the mess:
mkdir ~/semester_mess cd ~/semester_mess touch IC2_lab1.c IC2_lab2.c IC2_lab3.c IC2_notes.txt touch FP1_exercises.py FP1_notes.txt FP1_project.py touch ME2_homework.R ME2_data.csv ME2_notes.txt touch random_file.txt another_file.md backup_old.zip ls
Your goal, create this organised structure using only terminal commands:
~/organised_semester/ ├── IC2/ │ ├── labs/ ← .c files │ └── notes/ ← .txt files ├── FP1/ │ ├── code/ ← .py files │ └── notes/ ← .txt files ├── ME2/ │ ├── homework/ ← .R files │ ├── data/ ← .csv files │ └── notes/ ← .txt files └── other/ ← everything else
💡 Hints:
- Create the structure with
mkdir -pin one block - Use wildcards to move files:
mv IC2_*.c organised_semester/IC2/labs/ - Use
findto verify everything is in the right place:find organised_semester/ -name "*.c" - Check nothing is left behind:
ls ~/semester_mess/
Basic Linux commands exercises — Final Challenge
Exercise 4 — Basic file permissions
In Linux every file has permissions that control who can read, write and execute it. This is essential knowledge for IC2, especially when your compiled programs won’t run.
First, understand what you’re seeing. Run:
ls -l ~/GCID/IC2/Labs/Lab1_intro/
Output:
-rw-r--r--. 1 sergio sergio 0 Jun 7 10:23 main.c -rwxr-xr-x. 1 sergio sergio 8432 Jun 7 10:45 main
The permission string -rw-r--r-- breaks down like this:
- rw- r-- r-- ↑ ↑ ↑ ↑ │ │ │ └── other: can read only │ │ └────── group: can read only │ └────────── owner: can read and write └────────────── type: - = file, d = directory
Each group of 3 characters: r = read, w = write, x = execute, - = no permission.
The chmod command changes permissions. It uses numbers:
r = 4 w = 2 x = 1 rwx = 7 (4+2+1) rw- = 6 (4+2+0) r-- = 4 (4+0+0) --- = 0 (0+0+0)
chmod 755 file # rwxr-xr-x (owner all, group read+exec, other read+exec) chmod 644 file # rw-r--r-- (owner read+write, group read, other read) chmod 600 file # rw------- (owner read+write only, nobody else) chmod +x file # add execute permission for everyone chmod -x file # remove execute permission
Now the challenge
Set up:
mkdir ~/permissions_exercise cd ~/permissions_exercise touch secret.txt public.txt script.sh program.c gcc ~/GCID/IC2/Labs/Lab1_intro/main.c -o compiled_program 2>/dev/null || touch compiled_program ls -l
Task A: Make secret.txt readable and writable only by you — no one else can read it
(Target permissions: rw------- = 600)
Task B: Make public.txt readable by everyone but only writable by you
(Target permissions: rw-r--r-- = 644)
Task C: Make script.sh executable by you and readable by everyone
(Target permissions: rwxr--r-- = 744)
Task D: Try to run compiled_program — it probably fails. Fix the permissions so you can execute it, then run it.
Task E: Check what happens when you try to read a file with no read permissions:
chmod 000 secret.txt # remove all permissions cat secret.txt # try to read it chmod 600 secret.txt # restore your own permissions cat secret.txt # now it works
Task F: Use ls -l to verify each permission change worked correctly before moving to the next task.
💡 Hints:
chmod 600 secret.txt # rw------- chmod 644 public.txt # rw-r--r-- chmod 744 script.sh # rwxr--r-- chmod +x compiled_program # add execute ./compiled_program # run it (must be in same directory)
Commented solutions
Solution Exercise 1
# Setup mkdir ~/wildcard_exercise && cd ~/wildcard_exercise touch report_2023.txt report_2024.txt report_final.txt touch data_january.csv data_february.csv data_march.csv touch main.c utils.c header.h touch notes.txt backup.txt readme.md # Task A — list .txt files ls *.txt # Task B — list .c files ls *.c # Task C — files starting with report ls report* # Task D — files containing data ls *data* # Task E — move .csv files mkdir csv_files mv *.csv csv_files/ ls && ls csv_files/ # Task F — copy .c and .h files mkdir c_source cp *.c c_source/ cp *.h c_source/ # or in one command: cp *.c *.h c_source/ ls c_source/ # Task G — delete backup files rm backup* ls
Solution Exercise 2
# Setup mkdir -p ~/path_exercise/ProjectA/src mkdir -p ~/path_exercise/ProjectA/docs mkdir -p ~/path_exercise/ProjectB/src mkdir -p ~/path_exercise/shared cd ~/path_exercise # Task A — from ~/path_exercise, relative path touch ProjectA/src/main.c # Task B — from ProjectA/src, relative path to ProjectB/src cd ProjectA/src touch ../../ProjectB/src/utils.c ls ../../ProjectB/src/ # Task C — absolute paths (replace 'sergio' with your username) cp /home/sergio/path_exercise/ProjectA/src/main.c /home/sergio/path_exercise/shared/ ls /home/sergio/path_exercise/shared/ # Task D — from ProjectB/src, list ProjectA/docs cd ~/path_exercise/ProjectB/src ls ../../ProjectA/docs/ # Task E — from ProjectA/src to shared using only relative paths cd ~/path_exercise/ProjectA/src cd ../../shared pwd # should show ~/path_exercise/shared
Solution Exercise 3
# Setup mkdir ~/semester_mess && cd ~/semester_mess touch IC2_lab1.c IC2_lab2.c IC2_lab3.c IC2_notes.txt touch FP1_exercises.py FP1_notes.txt FP1_project.py touch ME2_homework.R ME2_data.csv ME2_notes.txt touch random_file.txt another_file.md backup_old.zip # Create organised structure mkdir -p ~/organised_semester/IC2/labs mkdir -p ~/organised_semester/IC2/notes mkdir -p ~/organised_semester/FP1/code mkdir -p ~/organised_semester/FP1/notes mkdir -p ~/organised_semester/ME2/homework mkdir -p ~/organised_semester/ME2/data mkdir -p ~/organised_semester/ME2/notes mkdir -p ~/organised_semester/other # Move files mv IC2_*.c ~/organised_semester/IC2/labs/ mv IC2_*.txt ~/organised_semester/IC2/notes/ mv FP1_*.py ~/organised_semester/FP1/code/ mv FP1_*.txt ~/organised_semester/FP1/notes/ mv ME2_*.R ~/organised_semester/ME2/homework/ mv ME2_*.csv ~/organised_semester/ME2/data/ mv ME2_*.txt ~/organised_semester/ME2/notes/ mv * ~/organised_semester/other/ 2>/dev/null; true # Verify find ~/organised_semester/ -name "*.c" find ~/organised_semester/ -name "*.py" ls ~/semester_mess/ # should be empty or nearly empty
Solution Exercise 4
# Setup mkdir ~/permissions_exercise && cd ~/permissions_exercise touch secret.txt public.txt script.sh compiled_program # Task A — rw------- (600) chmod 600 secret.txt ls -l secret.txt # -rw------- 1 sergio sergio 0 Jun 7 secret.txt # Task B — rw-r--r-- (644) chmod 644 public.txt ls -l public.txt # -rw-r--r-- 1 sergio sergio 0 Jun 7 public.txt # Task C — rwxr--r-- (744) chmod 744 script.sh ls -l script.sh # -rwxr--r-- 1 sergio sergio 0 Jun 7 script.sh # Task D — add execute permission and run chmod +x compiled_program ls -l compiled_program ./compiled_program # runs it (empty file will do nothing or give error) # Task E — remove all permissions and restore chmod 000 secret.txt cat secret.txt # Permission denied chmod 600 secret.txt cat secret.txt # works now (empty file) # Task F — verify all permissions ls -l
Cheat sheet — Linux commands and permissions
# ============================================ # CHEAT SHEET — Basic Linux Commands # Sergio Learns · sergiolearns.com # ============================================ # NAVIGATION pwd # where am I? ls # list current directory ls -la # detailed + hidden files ls -lh # with human-readable sizes cd folder # enter folder cd .. # go up one level cd ~ # go home from anywhere cd - # go back to previous location # CREATE mkdir folder # create directory mkdir -p a/b/c # create full path at once touch file.c # create empty file echo "text" > file # create file with content (overwrites) echo "text" >> file # append to file # VIEW cat file # show file contents less file # scroll through file (q to quit) head -n 20 file # show first 20 lines tail -n 20 file # show last 20 lines # COPY AND MOVE cp file copy # copy file cp -r folder/ backup/ # copy directory recursively mv file newname # rename mv file folder/ # move to directory # DELETE — no undo rm file # delete file rm -i file # delete with confirmation rm -r folder/ # delete directory rm -ri folder/ # delete with confirmation # WILDCARDS *.txt # any .txt file *.c # any .c file report* # files starting with report *data* # files containing data file?.txt # file1.txt, fileA.txt (one char) # SEARCH find folder/ -name "*.c" # find .c files find . -name "main*" # find files starting with main find ~ -name "*.py" -type f # find .py files (files only) # DISK AND MEMORY df -h # disk usage du -sh folder/ # folder size free -h # RAM usage # PERMISSIONS ls -l # show permissions chmod 755 file # rwxr-xr-x chmod 644 file # rw-r--r-- chmod 600 file # rw------- (private) chmod +x file # add execute permission chmod -x file # remove execute permission # PERMISSION NUMBERS r=4 w=2 x=1 7 = rwx 6 = rw- 5 = r-x 4 = r-- 0 = --- chmod XYZ: X=owner, Y=group, Z=other # OUTPUT FILTERING command | head -20 # first 20 lines command | tail -20 # last 20 lines command | grep word # lines containing word command | wc -l # count lines # USEFUL SHORTCUTS Tab → autocomplete ↑ ↓ → command history Ctrl+C → cancel running command Ctrl+L → clear screen !! → repeat last command # GOLDEN RULES # 1. pwd before rm — know where you are # 2. ls before rm — know what you're deleting # 3. rm -i or rm -ri for safety # 4. No spaces in filenames — use _ or - # 5. Linux is case sensitive # 6. . = current directory, .. = parent directory # 7. ~ = home directory, / = root
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