Software & AppsOperating SystemLinux

How To Kill an Unresponsive Program in Ubuntu Terminal

Ubuntu 15

In the world of Ubuntu, it’s not uncommon to come across a program that has stopped responding. When this happens, it’s important to know how to effectively terminate the unresponsive program to prevent it from consuming system resources. This article will guide you through several methods to kill an unresponsive program using the Ubuntu terminal.

Quick Answer

To kill an unresponsive program in Ubuntu Terminal, you have several options. You can use commands like pkill, top, htop, killall, ps, kill, or even xkill. Each command provides a different approach to terminating unresponsive programs, allowing you to regain control over your system’s resources.

Using the pkill Command

The pkill command is a powerful tool that allows you to send signals to processes by their names. To use pkill, simply type the command followed by the name of the unresponsive program. For example:

pkill totem

In this example, totem is the name of the unresponsive program. The pkill command will send a signal to all processes named “totem” and terminate them.

Using the top Command

The top command provides a dynamic, real-time view of the processes running on your system. To use top, type the command in your terminal:


You’ll see a list of processes currently running on your system. To kill a process, press k, then enter the PID (Process ID) of the unresponsive program, and press Enter twice. The PID can be found in the top output.

Using the htop Command

The htop command is similar to top, but with a more user-friendly interface. To use htop, type the command in your terminal:


From the htop interface, you can navigate to the unresponsive program, press k, and then press Enter to kill it. You can also use the t key to toggle tree view and see parent processes.

Using the killall Command

The killall command is another useful tool for terminating unresponsive programs. To use killall, type the command followed by the name of the unresponsive program:

killall totem

This command will kill all instances of the program named “totem”.

Using the ps and kill Commands

The ps command allows you to view the current processes. You can use it in combination with the grep command to find the unresponsive program:

ps -ef | grep totem

This command will display a list of processes containing the name “totem”. Once you’ve found the PID of the unresponsive program, you can use the kill command to terminate it:

kill -9 <PID>

Replace <PID> with the actual PID of the unresponsive program. The -9 option tells the system to forcefully kill the process.

Using the xkill Command

If none of the above methods work, you can try using the xkill command. Open a terminal and type xkill. Your cursor will turn into an “X”. Click on the window of the unresponsive program to force it to close.


Please note that you should use sudo if the program is started by another user. Be aware that killing a process can lead to data loss or system instability if the process is critical to system operation.

In conclusion, Ubuntu provides a plethora of commands to manage unresponsive programs. By understanding and utilizing these commands, you can maintain control over your system’s resources and keep your Ubuntu environment running smoothly.

How do I find the Process ID (PID) of an unresponsive program?

To find the PID of an unresponsive program, you can use the top or htop command. In the output of these commands, look for the column labeled "PID" to find the Process ID of the program.

What does the `-9` option in the `kill` command do?

The -9 option in the kill command is used to send a SIGKILL signal to the process, forcefully terminating it. This option should be used with caution as it does not allow the process to gracefully exit and may result in data loss or system instability.

Can I use these methods to kill system processes?

Yes, you can use these methods to kill system processes. However, it is important to exercise caution when terminating system processes as it can lead to system instability or unexpected behavior. Make sure you know the purpose of the process before terminating it.

What should I do if killing the unresponsive program doesn’t work?

If killing the unresponsive program using the mentioned methods doesn’t work, you can try restarting your system. This will terminate all running processes and can help resolve any issues caused by the unresponsive program.

Do I need to be a superuser (root) to use these commands?

Most of the commands mentioned in this article can be executed without superuser privileges. However, if the unresponsive program is started by another user, you may need to use sudo before the command to have the necessary permissions to terminate the process.

Leave a Comment

Your email address will not be published. Required fields are marked *