How to force kill process in Linux

1. Use pidof command to find the process ID of a running program or app. pidoff appname.
2. To kill process in Linux with PID: kill -9 pid.
3. To kill process in Linux with application name: killall -9 appname.

kill command examples to kill a process on Linux

1. Step 1 – Find out the PID (process id) of the lighttpd. Use the ps or pidof command to find out PID for any program.
2. Step 2 – kill the process using a PID. The PID # 3486 is assigned to the lighttpd process.
3. Step 3 – How to verify that the process is gone/killed.

The system will generate SIGKILL for a process itself under some unusual conditions where the program cannot possibly continue to run (even to run a signal handler). The SIGHUP (“hang-up”) signal is used to report that the user’s terminal is disconnected, perhaps because a network or telephone connection was broken.

In modern parlance this generally means it has lost its controlling tty. Unless you’ve taken care to detach from your tty, any program started in a given terminal will receive a SIGHUP when the terminal is closed.

The following are couple of examples.

1. SIGINT (Ctrl + C) – You know this already. Pressing Ctrl + C kills the running foreground process. This sends the SIGINT to the process to kill it.
2. You can send SIGQUIT signal to a process by pressing Ctrl + / or Ctrl + Y.

SIGHUP. The SIGHUP signal is sent to a process when its controlling terminal is closed. It was originally designed to notify the process of a serial line drop (a hangup). In modern systems, this signal usually means that the controlling pseudo or virtual terminal has been closed.

Let us get started. To kill a specific process, the command sends a signal to the process. By default, kill commands such as killall send a TERM signal that gracefully stops the specified process. Before we proceed to kill command, let us take a brief overview of the process signals.

The message that we try to communicate is also called notification that the destination process is to be processed. They might ignore the signals or leave to perform the default action. The kill command in Linux will allow users in sending a signal to the process.

SIGABRT – This SIGABRT kill signal is used for aborting the processing signal. Basically, a process is initiated to SIGABRT to kill the signal on its own. SIGBUS – Whenever a program sends the SIGBUS signal, it happens to be caused by a bus error.

Hangs up signals when controlling the terminal or at the end of the controlling processes. Signals when any unexpected mathematical operation is performed. When any of the process issues this signal, it will quit immediately. Signals to terminate the process or the software. Signals to stop the process in Linux.