Commands

# 1. Find the exact process.
pgrep -af <name>

# 2. Inspect the process before killing it.
ps -fp <pid>
pstree -aps <pid>

# 3. Prefer graceful stop.
kill -TERM <pid>

# 4. Verify.
pgrep -af <name>

# 5. Use force kill only when graceful stop fails.
kill -KILL <pid>

# Example 1: kill one process by keyword safely.
pgrep -af victorialogs
ps -fp 12345
kill -TERM 12345
pgrep -af victorialogs

# Example 2: process ignores TERM, then force kill.
kill -TERM 12345
sleep 5
ps -p 12345
kill -KILL 12345

# Example 3: find who owns a port, then stop it.
sudo lsof -i :8427
ps -fp <pid>
kill -TERM <pid>

# Example 4: systemd-managed service should be stopped by systemctl.
systemctl status vmauth
systemctl stop vmauth
systemctl status vmauth

# Example 5: use pkill only after previewing the exact matches.
pgrep -af 'python.*worker'
pkill -TERM -f 'python.*worker'
pgrep -af 'python.*worker'

# Example 6: kill by exact process name.
# This matches process name exactly, such as "nginx", not the full command line.
pgrep -x nginx
pkill -TERM -x nginx
pgrep -x nginx

kill:
    sends signal to PID

pkill:
    finds process by name/pattern and sends signal

-TERM:
    asks process to exit cleanly

-KILL:
    kernel kills process immediately
    process cannot clean up files, sockets, locks, or buffers

-f:
    matches full command line
    powerful but risky; inspect with pgrep -af first

systemd service:
    use systemctl stop <service> instead of killing MainPID directly
    otherwise systemd may restart it