How to Use killall Command in Linux: Syntax and Examples

The killall command in Linux terminates processes by their name instead of process ID. Use killall process_name to stop all processes matching that name quickly and easily.

Syntax

The basic syntax of killall is simple and consists of the command followed by options and the process name.

• killall [options] process_name: Sends a signal to all processes matching process_name.
• Options can modify behavior, like specifying the signal to send.

bash

killall [options] process_name

Example

This example shows how to use killall to stop all running instances of firefox by name.

bash

killall firefox

Output

firefox: no process found

Common Pitfalls

Common mistakes include:

• Using killall without root privileges when required, causing failure to kill some processes.
• Typing the wrong process name, which results in no processes being killed.
• Not specifying the correct signal if the default SIGTERM does not stop the process.

Always double-check the process name and consider using -9 option to force kill if needed.

bash

killall wrongname
killall -9 firefox

Output

killall: no process found

Quick Reference

Command	Description
killall process_name	Kill all processes with the given name using SIGTERM
killall -9 process_name	Force kill all processes with SIGKILL signal
killall -u username process_name	Kill processes by name owned by a specific user
killall -q process_name	Quiet mode, no output
killall -v process_name	Verbose mode, shows what is killed

Key Takeaways

Use killall process_name to terminate all processes by name quickly.

Specify signals like -9 to force kill if normal termination fails.

Ensure you have the right permissions to kill the target processes.

Double-check the process name to avoid killing unintended processes.

Use options like -u to target processes by user.