killall — Terminate processes by name

Linux / Service and process management / killall.html

Sends a signal to every process whose name matches.

Basic Information

What is this command?

killall targets processes by name instead of PID.

The default signal is TERM; numeric or named signals request forced termination or reload.

What problems does it solve?

• Clean up every instance of the same program at once.
• Send HUP to reload configuration.
• Remove leftover instances in one step.
• Keep cleanup steps in scripts short.

Key features

Graceful termination

Without a signal it sends TERM and asks the process to exit.

• When to use: When a graceful stop is intended
• What you get: Process exits after cleanup
• Limitations: Processes ignoring TERM stay alive

Choosing a signal

Pass a signal name or number to change the effect.

• When to use: For reloads or forced stops
• What you get: HUP reloads, KILL stops immediately
• Limitations: KILL skips cleanup

Checking targets

Use -i for interactive confirmation or -w to wait for exit.

• When to use: When accidental kills are a risk
• What you get: Confirmation or wait-for-exit
• Limitations: Overlapping names may match unintended targets

Installation and usage

Check whether it is installed

killall -V

apt install psmisc # Debian/Ubuntu dnf install psmisc # Fedora/RHEL

Real-world examples

Graceful stop

Stop all nginx processes.

# Ask all nginx processes to exit
killall nginx

Reload

Send HUP so the process reloads.

# Reload configuration without stopping
killall -HUP nginx

Confirm before killing

Ask before each kill.

# Ask for confirmation before each match
killall -i nginx