Introduction
You might have faced a situation where you have launched an application, and suddenly while using the app, your app or system starts to crash unexpectedly or becomes unresponsive. There are situations where the cloud system running Linux may not respond. If you try to start the application again, you need to close it first.
But if your application fails to stop or shut down completely, you will not be able to start it again. Well, we all have faced such a critical situation at least once in our life. To solve such an issue, you have to kill or terminate your application process. But now the question is how? In this article, you will understand two different approaches to kill all processes in Linux.
Topics:
- How to Kill all process in Linux
- The killall command
- How to use killall command in Linux
- How to kill a process in Linux using kill command?
- Conclusion
How to killall process in Linux?
Various cloud providers deliver cloud services that use Linux. In Linux, each daemon or program is a process that represents a single running program. You can fetch the list of all your running processes with the ‘ps’ command. When you run an application, it demands a certain amount of memory and processing power. The more processes your system will run, the more CPU cycles and memory you will require.
When an application fails to close, it keeps on eating up memory and processing power. Luckily, you can efficiently kill a process in Linux because Linux provides different utilities or utility commands that help you to terminate errant processes. Without further ado, let us now dig into the two distinct Linux kill process commands and killall commands, and how they work.
The killall command –
The killall command in Linux is a utility command used for killing any running process on the system based on a given name. This command will terminate the processes forcibly when a specified name matches.
The easiest way to kill a bunch of processes altogether is through the killall command. The kill all command in Linux will first send a signal to every running daemon. If you do not specify any signal name, by default, it sends the SIGTERM. We can define our signal name using the number (example -1) or via options (example: -s).
How to use killall command in Linux?
The basic structure of killall command is
killall [process name]
where process name will be the name of the process already running in your system and you want to terminate. Here are some of the killall options –
killall [-Z, --context pattern]: It will kill only those processes that have security context.
[-e, --exact]: This argument checks for the exact match in the case of very long names.
[-g, --process-group]: It will kill the entire process group to which the process belongs.
[-i, --interactive]: It asks for confirmation before killing a process.
[-o, --older-than TIME]: It checks for the process match that is older than the mentioned time.
[-q, --quiet]: It does not show any message if the killall does not find any process to kill.
[-r, --regexp]: It matches the process-name pattern as mentioned in the regular expression.
[-u, --user user]: It kills only those processes a particular user owns.
[-v, --verbose]: It reports whether the signal was sent successfully or not.
[-w, --wait]: It makes the system wait for all kill processes to die.
[-y, --younger-than TIME]: It matches only those processes that are younger than the specified time.
[-I, --ignore-case]: It checks for process names without case sensitivity.
[-V, --version]: It shows the version information.
How to kill a process in Linux using kill command?
The kill command is a built-in shell command. It is a standalone /bin/kill executable that terminates a specific process based on the given process ID (PID). For listing all the available signals, you have to use the -l option. If you do not specify any option, the kill command will send the SIGTERM to the process ID (PID) and ask that particular daemon or service to shut itself down. The format for using the kill command is
kill [PID]
To send a signal to a process, the structure is:
kill {-signal | -s signal} [PID]
Here are some of the kill options –
kill [-s, --signal]: It tells the number of signals the ‘kill’ will send.
[pid]: This argument allows us to specify the numeric process ID. If you are not sure about the process ID number, you can use the ps command to get a list of all the process IDs.
[-l, --list]: It lists all the different signal names.
[-L, --table]: It lists all available signal names along with numbers in a tabular format.
Conclusion
Process termination is an essential utility every Linux operator must know. E2E Cloud renders Linux-based systems where you can run multiple processes. If you ever fail to stop any daemon, the Linux kill process and killall Linux command will help you rescue.
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