Linux Command Line Cheatsheet

Quick Reference Guide for Command Line Operations

1 📍 Basic Navigation & File Inspection

1. ~ — Home directory
   
2. pwd — Print current working directory
   
3. ls — List directory contents
   • -l — Long format (e.g., ls -l)
     
   • -lt — Long format, sorted by time (newest first)
     
   • -ltr — Long format, sorted by time (oldest first)
     
   • -ltrh — Long format, oldest first, human-readable sizes
     
   • -a — Show all files including hidden ones
     
   • -1 - Show 1 file per line
4. cd folder_name — Change directory
   • cd .. — Go to parent directory
     
   • cd . — Stay in current directory
     
5. find — find files
   • e.g., find . -name "*fish*": find all the files whose name contains fish

---

2 📍 Viewing File Content

5. cat file.txt — Print entire content
   
6. head file.txt — Print first 10 lines
   
7. tail file.txt — Print last 10 lines

---

3 📍 Editing Files

8. nano file.txt — Open file in Nano editor
   • Ctrl+O to save, Ctrl+X to exit, Ctrl+K to delete a line
     
9. vi file.txt — Open file in Vi editor
   • Press i to insert
     
   • Press Esc, then type :wq and hit Enter to save and quit
     
   • Type :q! and hit Enter to quit without saving

---

4 📍 Creating and Modifying Files

10. touch file.txt — Create an empty file or update timestamp if the file already exist
11. echo "text" > file.txt — Write text to file (overwrite)
    
12. echo "text" >> file.txt — Append text to file
    
13. cat file1.txt file2.txt > file3.txt — Combine files

---

5 📍 File Movement, Copying, and Deletion

14. mv oldname.txt newname.txt — Rename a file
    
15. mv file.txt folder/ — Move file to folder
    
16. cp file.txt copy.txt — Copy file
    
17. cp -r folder1 folder2 — Copy folder recursively
    
18. rm file.txt — Delete a file
    
19. rm -r folder/ — Recursively delete folder
    
20. rm -f file.txt — Force delete file (no warning)
    
21. rm -rf folder/ — Forcefully delete folder and contents

---

6 📍 Directory Management

22. mkdir new_folder — Create a new folder
    
23. mkdir -p parent/child — Create nested folders including parent folders if parent folders do not exist yet
24. rmdir empty_folder — Remove empty folder

---

7 📍 Permissions & Ownership

25. chmod 400 key.pem — Change file permission
    • first digit = privillage of owner of the file; second digit = other people in the same group; third digit = everyone else in the world
    • 4 = read, 2 = write, 1 = execute
      
    • 7 = 4 + 2 + 1 = read & write & execute
    • Examples:
      • 400 = read-only by owner
        
      • 600 = read/write by owner
        
      • 756 = full access for owner, read & execute for others in the same group, read & write for everyone else in the world
26. chown user:group folder/ — Change ownership of the folder
27. sudo — Run command with superuser privileges, “super user do”

---

8 📍 Wildcards & Patterns

28. * — Wildcard: matches anything
    • Example: mv fish* folder/
      
29. ? — Matches a single unknown character

---

9 📍 Print and Search

30. echo "text" — Print text to terminal
    
31. grep pattern file.txt — Search for pattern
    • -i — Ignore case
      
    • -v — Display lines with no match
    • -n — precede each matching line with line number
    • -c — Print only total count of matched lines

---

10 📍 System & File Info

32. history — Show command history
    
33. df -h — Show disk space in human-readable format
    
34. clear — Clear the screen
    
35. wc file.txt — Count number of words in this file
    • -l — Count number of lines in this file
36. sort file.txt — Sort lines alphabetically

---

11 📍 Compression

37. zip file.zip file.txt — Compress file
    
38. unzip file.zip — Decompress file

---

12 📍 Process Management

39. Ctrl+C — Stop running command
    
40. exit — exit the SSH connection to a server, or exit a mode of being a user
41. COMMAND FILE1 | COMMAND — Connect output of commands
    • for instance, cat FILE1 | sort