Linux Command Line: The 50 Commands Every Developer Needs (2026)

You don't need to memorize thousands of commands. These 50 cover 95% of what you'll do daily as a developer.

File & Directory Operations

# Navigation
pwd                          # Where am I?
cd ~/projects                 # Go to directory
cd -                          # Go to previous directory
ls -lah                      # List files (long, human-readable, hidden)

# Finding things
find . -name "*.js"          # Find by name (recursive)
find . -type f -mtime -7     # Files modified in last 7 days
grep -r "TODO" ./src         # Search file contents recursively
rg "function" ./src          # Ripgrep — faster alternative

# File operations
cp file.txt backup.txt       # Copy
cp -r folder/ backup/        # Copy directory
mv old.txt new.txt           # Move/rename
rm file.txt                  # Delete (gone forever!)
rm -rf folder/               # Delete directory + contents
mkdir -p a/b/c/d             # Create nested directories
touch newfile.js             # Create empty file
ln -s /path/to/file link     # Create symbolic link

# Viewing files
cat file.txt                 # Show entire file
less file.txt                # Scroll through (q to quit)
head -20 file.txt            # First 20 lines
tail -f logfile.log          # Last lines + follow live updates!
wc -l file.txt               # Count lines
du -sh *                      # Disk usage per item (human-readable)

Text Processing

# Search within files
grep "error" app.log         # Find matching lines
grep -n "error" app.log      # With line numbers
grep -C 3 "error" app.log    # Show 3 lines before/after match
grep -r "import" src/        # Recursive search in directory

# Find and replace
sed 's/old/new/g' file.txt   # Replace all occurrences
sed -i.bak 's/foo/bar/g' *  # In-place replace with backup

# Stream editing with awk
awk '{print $1, $3}' data.txt # Print columns 1 and 3
awk '/error/{count++} END {print count}' log.txt # Count matches

# Sort & unique
sort names.txt               # Alphabetical sort
sort -rn numbers.txt         # Reverse numeric sort
sort file.txt | uniq -c      # Count occurrences

Process Management

# What's running?
ps aux                       # All processes
top / htop                   # Interactive viewers (q to quit)
pgrep node                   # Find PIDs of node processes

# Controlling processes
kill PID                     # Graceful stop (SIGTERM)
kill -9 PID                 # Force kill (SIGKILL) — last resort
pkill -f "node server"      # Kill by name pattern

# Background jobs
command &                    # Run in background
nohup long-job &             # Survives terminal close
Ctrl+Z                        # Suspend current job
bg                           # Resume suspended job in background
fg                           # Bring to foreground
jobs                         # List background jobs

# Resource monitoring
free -h                      # Memory usage
df -h                        # Disk space
iotop                        # Disk I/O per process
nethogs                      # Network bandwidth per process
vmstat 1                     # System stats every second

Networking

# Connection testing
ping google.com              # Basic connectivity
curl -I https://example.com # HTTP headers only
curl -v https://api.test.com # Verbose request/response

# DNS
dig example.com              # Full DNS info
nslookup example.com         # Simple lookup

# Port checking
ss -tlnp                    # Listening ports + PIDs
nc -zv localhost:3000        # Test if port responds

# SSH essentials
ssh user@host                # Connect to remote
ssh -i key.pem user@host     # Connect with specific key
scp file.txt user@host:/path/ # Copy TO server
scp user@host:/path/file ./   # Copy FROM server
ssh-keygen -t ed25519        # Generate SSH key pair
ssh-copy-id user@host        # Copy public key to server

Permissions & Users

# Permission breakdown: rwx rwx rwx
# Owner | Group | Others
# r=4, w=2, x=1 → 7=rwx, 5=r-x, 6=rw-

chmod 755 script.sh           # Owner=rwx, Group+Others=rx
chmod 600 secret.key          # Only owner can read/write
chown www-data:www-data /var/www/html  # Change owner+group

# Sudo
sudo visudo                  # Edit sudoers safely
# deploy ALL=(ALL) NOPASSWD: /usr/bin/systemctl restart nginx

DevOps Essentials

# Package management (Debian/Ubuntu)
sudo apt update && sudo apt upgrade -y
sudo apt install nginx
apt search docker

# Systemd services
systemctl status nginx       # Service status
systemctl start nginx        # Start
systemctl restart nginx       # Restart
systemctl enable nginx        # Start on boot
journalctl -u nginx -f        # Follow logs live

# Docker basics
docker ps                    # Running containers
docker images                # Available images
docker exec -it container sh  # Enter container
docker logs -f container      # Follow logs
docker system prune -a        # Clean up unused resources

# Git quick reference
git status                   # Working tree status
git diff                      # Unstaged changes
git add -A && git commit -m "msg"  # Stage + commit
git push origin main          # Push
git log --oneline -10         # Recent commits compact

Power User Chaining

# Pipe: output of one command = input of next
cat access.log | grep "404" | wc -l          # Count 404 errors
ps aux | grep node | awk '{print $2}' | xargs kill  # Kill all node procs

# Redirect output:
command > out.txt          # Write to file (overwrite)
command >> out.txt         # Append to file
command 2> err.txt         # Write stderr to file
command < input.txt        # Read from file

# Combine tools for real workflows:

# Find largest files:
du -sh * | sort -rh | head -10

# Find and delete old log files:
find /var/log -type f -mtime +30 -name "*.log" -delete

# Monitor real-time errors:
tail -f /var/log/app.log | grep --line-buffered ERROR

# Quick HTTP server from any directory:
python3 -m http.server 8000

# Batch rename (add date prefix):
for f in *.jpg; do mv "$f" "$(date +%Y%m%d)_$f"; done

# Extract any archive (universal extract function):
extract() {
  if [ -f $1 ] ; then
    case $1 in
      *.tar.bz2)  tar xjf $1 ;;
      *.tar.gz)   tar xzf $1 ;;
      *.bz2)      bunzip2 $1 ;;
      *.rar)      unrar x $1 ;;
      *.gz)       gunzip $1 ;;
      *.tar)      tar xf $1 ;;
      *.tbz2)     tar xjf $1 ;;
      *.tgz)      tar xzf $1 ;;
      *.zip)      unzip $1 ;;
      *.Z)        uncompress $1 ;;
      *)          echo "'$1' cannot be extracted via extract()" ;;
    esac
  else
    echo "'$1' is not a valid file"
  fi
}

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Which command here is new to you? What's your favorite CLI trick that wasn't included?

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