Process Commands

kill Linux Command

Sends a signal to terminate a process by its PID.

What does kill do?

Sends a signal to terminate a process by its PID.

kill [options] PID

kill -9 1234

What does kill -9 do?

Sends SIGKILL (signal 9) which immediately terminates the process without allowing cleanup. Use as a last resort when normal termination fails.

What is the difference between kill and kill -9?

Default kill sends SIGTERM (15), allowing graceful shutdown. kill -9 sends SIGKILL which forces immediate termination without cleanup.

How do I kill a process by name?

Use `killall processname` or `pkill processname` instead of `kill`. You can also use `pgrep processname | xargs kill`.

How do I kill all processes of a user?

Use `sudo killall -u username` to kill all processes owned by a specific user. Use with caution.

What signals can I send with kill?

Common signals: 15=SIGTERM (default), 9=SIGKILL, 1=SIGHUP, 2=SIGINT, 20=SIGTSTP. Use `kill -l` to see all signals.

How do I see what signal a process received?

Use `dmesg | grep 'killed process'` to see recently killed processes and the signal that was sent.

How do I send SIGHUP to a process?

Use `kill -1 PID` to send SIGHUP, which typically tells a process to reload its configuration without restarting.

How do I stop a process gracefully?

First try `kill PID` (SIGTERM) to allow the process to clean up. Only use `kill -9 PID` if the process doesn't respond to SIGTERM.

Enhanced, more user-friendly version of top with color and mouse support.

Kills all processes matching a given name.

Displays an interactive, real-time view of system processes and resource usage.

Sends a signal to processes based on name and other attributes.

Reports a snapshot of current running processes with their PIDs.

Resumes a suspended job in the background.