Complete Process Management Guide — ps · kill · nice · htop

# Current session processes
ps

# All processes (BSD style)
ps aux

# All processes (Unix style)
ps -ef

# Search for a specific process
ps aux | grep nginx

# View as a tree
ps axjf
pstree -p

# Processes for a specific user
ps -u deploy

# Sort by CPU / memory
ps aux --sort=-%cpu | head -10
ps aux --sort=-%mem | head -10

# Default terminate (SIGTERM, 15 — graceful shutdown request)
kill 1234

# Force kill (SIGKILL, 9 — immediate termination)
kill -9 1234
kill -KILL 1234

# Kill by process name
pkill nginx
pkill -9 node

# Signal all matching processes
killall nginx

# List signals
kill -l

# Run at lower priority (background work)
nice -n 10 tar czf backup.tar.gz /data

# Higher priority (requires root)
sudo nice -n -10 ./critical-process

# Change priority of a running process
renice -n 5 -p 1234        # By PID
renice -n 10 -u deploy     # By user

# Check current priority
ps -o pid,ni,comm -p 1234

sudo apt install -y htop
htop

# Run in background
./long-task.sh &

# Job list
jobs

# Bring to foreground
fg %1

# Send to background (after Ctrl+Z)
bg %1

# Keep running after terminal closes
nohup ./script.sh > output.log 2>&1 &

# Detach a running process
disown %1