{"id":3124,"date":"2024-06-02T10:00:57","date_gmt":"2024-06-02T10:00:57","guid":{"rendered":"https:\/\/draculaservers.com\/tutorials\/?p=3124"},"modified":"2024-07-01T08:53:05","modified_gmt":"2024-07-01T08:53:05","slug":"how-to-kill-processes-in-ubuntu-comprehensive-guid","status":"publish","type":"post","link":"https:\/\/draculaservers.com\/tutorials\/how-to-kill-processes-in-ubuntu-comprehensive-guid\/","title":{"rendered":"How to Kill Processes in Ubuntu? | Comprehensive Guid"},"content":{"rendered":"

Killing Processes essentially means stopping their execution instantly without allowing them to execute the closing protocols.<\/p>\n

In Ubuntu and other Linux Distributions, there comes a time when a certain command or application needs to be closed manually. This is often true when a command or application is not responding or consuming too many resources. This guide will show you the step-by-step procedure for killing processes in Ubuntu and the different commands that can be used for this purpose.<\/p>\n\n

Let\u2019s get started!<\/p>\n

How to Kill Processes in Ubuntu?<\/h2>\n

To Kill a Process in Ubuntu, you must first find its process ID (PID). After that, use a kill command of your choice while specifying the termination signal to be sent to the process. Alternatively, you can use the GUI tool System Monitor to kill the process of your choice.<\/p>\n

There are quite a few built-in commands that help you locate the process ID of a process and, similarly, a few commands that allow you to kill the process. However, the main thing is the signal sent to the process. Based on the signal, you can use the same command to stop, kill, or continue a process\u2019s execution.<\/p>\n

Let\u2019s discuss the different steps for killing a process in order.<\/p>\n

Locate the Process\u2019s ID (PID)<\/h3>\n

The first step is to locate the ID of the process or application that you want to kill. As mentioned earlier, multiple Ubuntu commands can help you find the PID. Let\u2019s go over some of such commands.<\/p>\n

1. The \u201cps aux\u201d Command<\/h4>\n

The ps aux command displays the process IDs of all processes running on your Ubuntu machine, including the root processes. To use this command, simply open up a new terminal (CTRL + ALT + T<\/strong>), type \u201cps aux<\/strong>,\u201d and hit the \u201cEnter<\/strong>\u201d key. Upon executing, you will see the following output on the terminal session.<\/p>\n

\"How<\/a><\/p>\n

As you can see from the screenshot, it starts the processes from PID 1 till the very last process. Find the PID of the process you want to kill from the list. However, this is a long list, and scrolling through this list is not a smart way. Therefore, you can choose to go for another command. The \u201cps aux\u201d command is useful when you want to find the PID of system processes.<\/p>\n

2. The \u201cpidof\u201d Command<\/h4>\n

The second command, \u201cpidof,\u201d takes in the name of the application whose process ID you want to find and returns all the IDs of this application’s subprocesses. To demonstrate the working of this command, let\u2019s try to find the ID of \u201cfirefox<\/strong>.\u201d Open up a new terminal and type the following command inside it.<\/p>\n

pidof firefox<\/pre>\n
When you execute the above command, you will get the following output displayed on the terminal session.<\/p>\n
\"How<\/a><\/p>\n
As you can see from the output image, the application Firefox has multiple PIDs because It is running multiple subprocesses. If you want to kill the entire tree of Firefox, you will use the lowest ID because the lowest PID is the parent ID of that application.<\/p>\n
3. The \u201cpgrep\u201d<\/strong> Command<\/strong><\/h4>\n
The third command you can use to find the process ID is the \u201cpgrep\u201d command. This command is used the same exact way as the \u201cpidof\u201d command, with the only difference being that it doesn\u2019t return the PIDs of subprocesses. It only returns the PID of the parent process of the specified application\/process.<\/p>\n
To use this command to find Firefox’s process ID, open a new terminal session and type the following command inside.<\/p>\n
pgrep firefox<\/pre>\n
You will get the following output on the terminal when you execute the command.<\/p>\n
\"How<\/a><\/p>\n
You can see that the \u201cpgrep<\/strong>\u201d command has returned only one ID, Firefox’s root process ID. However, if the application runs multiple trees, the \u201cpgrep<\/strong>\u201d command will return the root process ID for each tree.<\/p>\n
\"How<\/a><\/p>\n
4. The \u201cps\u201d and \u201cgrep\u201d Command<\/h4>\n
In this method, you will get the output of the \u201cps aux\u201d command and filter it out using the \u201cgrep\u201d command to find the ID of your desired application\/process. For example, if you want to find the process ID of firefox, use the following command.<\/p>\n
ps aux | grep -i \u201cfirefox\u201d<\/pre>\n
Running this command will result in the following output on the terminal session.<\/p>\n
\"How<\/a><\/p>\n
The process ID is displayed in the second column of the output, which, in this case, is 5287<\/strong>.<\/p>\n
Kill the Process Using Kill Commands<\/h3>\n
Once you have figured out the process you want to kill, the next step is simply using a kill command and sending a termination signal to a specific PID. Let\u2019s look at some commands and their methods.<\/p>\n
1. The \u201ckill\u201d Command<\/h4>\n
The first command you can use to kill processes in Ubuntu is the Kill command. The Kill command is used to send different signals to a given process. But for now, let\u2019s focus on the signal flag \u201c-9<\/strong>\u201d, used for forceful termination.<\/p>\n
To kill a process using the kill command, use the following command template.<\/p>\n
kill -9 {process ID}<\/pre>\n
To demonstrate this, let\u2019s try killing the process \u201cfirefox\u201d using the following command.<\/p>\n
kill -9 5407<\/pre>\n
When you execute the command, the terminal will not display any confirmation message.<\/p>\n
\"How<\/a><\/p>\n
However, make sure to use the PID that you have on your machine. As you can see, the command \u201cpidof<\/strong>\u201d has been used to find the process ID of firefox. Anyhow, the next step is to verify that the process has been terminated. To do this, again run the \u201cpidof<\/strong> firefox\u201d command.<\/p>\n
\"How<\/a><\/p>\n
As you can see in the output image, the \u201cpidof<\/strong>\u201d command didn\u2019t return any process ID. This ensures that the process has been successfully killed.<\/p>\n
As mentioned earlier, the kill command can send different signals to the process. These signals are as follows.<\/p>\n