25 Linux Command-Line Tricks Every Admin Should Know

Level Up Your Command Line Skills

The command line is where productivity happens. These 25 tricks will save you time, reduce errors, and make you a more efficient Linux administrator. Bookmark this page—you'll reference it often.

Navigation and History

1. Jump to Previous Directory

cd -   # Toggle between current and previous directory

2. Return Home Instantly

cd     # No arguments = home directory

3. Search Command History

Ctrl+R   # Reverse search, type to find previous commands
!!       # Repeat last command
!$       # Last argument of previous command

4. Fix Typos in Previous Command

^typo^correction   # Replace first occurrence
# Example: ^sl^ls

File Operations

5. Create Nested Directories

mkdir -p path/to/deep/directory   # Creates all parent dirs

6. Create Multiple Files at Once

touch file{1..10}.txt   # Creates file1.txt through file10.txt

7. Backup File with Timestamp

cp file.conf{,.bak-$(date +%Y%m%d)}   # Creates file.conf.bak-20260204

8. Move File and Follow It

mv file.txt /new/path/ && cd $_   # Move and cd to destination

Text Processing

9. View Large Files Efficiently

less +F filename   # Follow mode like tail -f, Ctrl+C to stop

10. Extract Specific Columns

awk '{print $1, $3}' file.txt   # Print columns 1 and 3
cut -d':' -f1 /etc/passwd         # Cut by delimiter

11. Count Lines/Words/Characters

wc -l file.txt   # Lines only
wc -w file.txt   # Words only

12. Find and Replace in File

sed -i 's/old/new/g' file.txt   # In-place replace all occurrences

Process Management

13. Run Command Immune to Hangups

nohup long-running-command &   # Continues after logout
disown %1                       # Disown running background job

14. Kill Process by Name

pkill -f process_name   # Kill by pattern match
killall nginx           # Kill all by exact name

15. Monitor Process Resources

watch -n 1 'ps aux --sort=-%mem | head'   # Top memory users, refresh 1s

Network Utilities

16. Quick Port Check

ss -tulnp | grep :80        # What's using port 80?
lsof -i :3000               # More details about port 3000

17. Download with Progress

curl -# -O https://example.com/file.zip   # Progress bar download

18. Test Port Connectivity

nc -zv hostname 22   # Check if SSH port is open
timeout 3 bash -c 'cat < /dev/null > /dev/tcp/host/port'   # Bash native

Disk and Storage

19. Find Disk Space Hogs

du -h --max-depth=1 | sort -hr   # Largest directories
ncdu /                            # Interactive disk usage (install ncdu)

20. Find Large Files

find / -type f -size +100M 2>/dev/null   # Files over 100MB

Productivity Boosters

21. Run Multiple Commands

cmd1 && cmd2   # Run cmd2 only if cmd1 succeeds
cmd1 || cmd2   # Run cmd2 only if cmd1 fails
cmd1 ; cmd2    # Run both regardless

22. Parallel Execution

cat hosts.txt | xargs -P 4 -I {} ssh {} 'uptime'   # 4 parallel SSH commands

23. Watch Command Output

watch -d df -h   # Highlight differences each refresh

24. Quick Calculations

echo $((1024 * 1024))    # Bash arithmetic
bc <<< "scale=2; 100/3"  # Floating point

25. Create Aliases for Common Commands

# Add to ~/.bashrc
alias ll='ls -la'
alias ..='cd ..'
alias gs='git status'
alias k='kubectl'
alias tf='terraform'

Bonus: Essential Key Combinations

• Ctrl+A - Move cursor to start of line
• Ctrl+E - Move cursor to end of line
• Ctrl+U - Delete from cursor to start
• Ctrl+K - Delete from cursor to end
• Ctrl+W - Delete previous word
• Ctrl+L - Clear screen
• Ctrl+Z - Suspend current process (fg to resume)

Conclusion

These tricks become second nature with practice. Start with a few, use them daily, and gradually expand your repertoire. Your future self will thank you.

Want more? Our Linux command-line eBooks dive deep into shell productivity and advanced techniques.