Killing Commands in Linux

What is the Kill Command?

The kill command is a Linux command line utility used to terminate or signal processes based on their process identification numbers (PIDs). This command is useful for ending unresponsive processes, such as those that are stuck in an infinite loop or no longer responding to user input. It is also used by system administrators to manage processes on remote systems.

How Does the Kill Command Work?

The kill command uses signals to send instructions to running processes. These signals can be used to terminate the process, ask it to pause or restart, or various other actions. Each signal is represented by a number, though there are also mnemonic names for each signal. To send a signal to a process, you must know its PID.

Using the Kill Command

To use the kill command, you must first determine the PID of the process you wish to kill. The PID can be found with the command “ps -ef”. Once you have the PID, you can send a signal to the process with the command “kill -[signal] [PID]”. The signal can be a number or a mnemonic name. Signals are documented here: http://man7.org/linux/man-pages/man7/signal.7.html For example, to terminate an unresponsive process with a PID of 1234, you would type “kill -15 1234”.

Conclusion

The kill command is an essential tool for managing processes in Linux. It can be used to end unresponsive processes, as well as signal them to pause or restart. By sending the appropriate signal to a PID, you can take control of any process.