I have a process I can't kill with kill -9 . What's the problem in such a case, especially since I am the owner of that process. I thought nothing could evade that kill option.

99% of the time, sudo kill -9 on a user space process will result in a (relatively) successful termination. However, what extra considerations might there be for killing kernel tasks? A sample scenario might be field testing a new device driver where I also have a watchdog process that monitors the driver. If my watchdog detects the driver status API returning a fatal error condition, the driver not responding within a few seconds, excessive CPU usage, corruption of the code segment, etc, how safe is it to just kill and restart the process kernel module, ignoring issues like leaving the device it is driving in an intermediate state? If lsmod shows it is being used by other modules, are there other issues to consider? [This is a related question](https://unix.stackexchange.com/q/152090/46316) as I envisage my driver starting on init.

How do I kill a process that cannot be killed?

user@kubuntu22:~$ ps -ef |grep smbd
nobody   3532354       1  0 16:30 ?        00:00:00 /usr/sbin/smbd --foreground --no-process-group

user@kubuntu22:~$ sudo killall smbd

user@kubuntu22:~$ ps -ef |grep smbd
nobody   3532354       1  0 16:30 ?        00:00:00 /usr/sbin/smbd --foreground --no-process-group

user@kubuntu22:~$ sudo killall -KILL smbd

user@kubuntu22:~$ ps -ef |grep smbd
nobody   3532354       1  0 16:30 ?        00:00:00 /usr/sbin/smbd --foreground --no-process-group

user@kubuntu22:~$ sudo kill -9 3532354

user@kubuntu22:~$ ps -ef |grep smbd
nobody   3532354       1  0 16:30 ?        00:00:00 /usr/sbin/smbd --foreground --no-process-group

System information: (Ubuntu 22.04.5 LTS jammy Linux 6.5.0-35-generic x86_64) Edit:

user@kubuntu22:~$ ps ax |grep smbd
3532354 ?        D      0:00 /usr/sbin/smbd --foreground --no-process-group

I guess it's stuck in the "erroneous uninterruptible sleep " state (D) And it has the network port open so running another smbd works but I can't connect.

@kubuntu22:~$ sudo netstat -tunap |grep smbd
tcp        0      0 0.0.0.0:139             0.0.0.0:*               LISTEN      3564116/smbd        
tcp        0      0 0.0.0.0:445             0.0.0.0:*               LISTEN      3564116/smbd        
tcp     1117      0 127.0.0.1:445           127.0.0.1:41882         CLOSE_WAIT  3532354/smbd        
tcp6       0      0 :::139                  :::*                    LISTEN      3564116/smbd        
tcp6       0      0 :::445                  :::*                    LISTEN      3564116/smbd

I often start to read a huge file and then want to quit after a while, but there is a lag from pressing
Ctrl+C to the program stops. Is there a chance of shortening the lag by pressing the Ctrl+C key several times? Or am I wasting my keypresses?

According to BASH manual page, > When Bash receives a SIGINT, it breaks out of any executing loops. In > all cases, Bash ignores SIGQUIT. So if there was a shell script, started from bash shell, to which a SIGINT or SIGQUIT is sent via the following commands, they have no effect on the script. The script still keeps on running. $ /usr/bin/kill --verbose --signal SIGQUIT > sending signal 3 to pid > $ /usr/bin/kill --verbose --signal SIGINT > sending signal 2 to pid > So how can a SIGQUIT or SIGINT be sent from a bash interactive shell to a shell script that has been started by another bash shell? However if application or script is started from **systemd-user** then it receives both the signals SIGQUIT and SIGINT. SIGQUIT has the benefit of creating a core dump when the script or application exits.

I've had this issue on several machines. Is there some way to free this blocked port? Here is an example: Let me explain. I've killed some JAVA-Process on SUSE Linux Enterprise Server 11 SP4, which had some ports open. I used the command "kill -9 " with root user. Now it is not possible to start the process again, because the port is still blocked. The application dies when the port is still open. But the process is definitively gone! When I have a look with command netstat -anop | grep -E "Sta|37941" (also with root user), I'll get the following results: Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name Timer [...] tcp 0 0 172.21.63.27:42034 172.21.63.28:37941 ESTABLISHED - keepalive (2861.75/0/0) [...] It shows no PID! Before killing the process, it showed the PID of the process. Is there any way to free such a "dead" port? We are always need to restart the operating system to get the application started again. But this is really, really critical in our high-availability systems... so what to do if we need to kill the process in the future? This issue also happened on other unix operating systems in the past. Any help in solving this issue for the future would be highly appreciated. Thank you all very much in advance!

I used to take thread dumps using:

kill -3 pidof java

This creates thread dumps in catalina.out. How can I get that output into a different file instead of catalina.out? Usually, the kill command doesn’t output to stdout or stderr, so we can't capture it by redirecting script output or using exec at the beginning. Is there any way to do this?

I expect to get some flak for this, but I can't find the answer anywhere. It seems like it should be so obvious. Sometimes, when I type a bad command in a bash terminal, the cursor just jumps down to the next line without any error or anything. I can't tell what I did wrong. It's like I'm stuck in the program. Reenactment: $ tidy Me: "Oops! That's not what I meant to type..." :q Me: "That didn't work..." :exit :quit exit quit /exit /quit -exit -quit -wtf??? I know I screwed up but how do I get back to the prompt without closing the terminal?

I am CentOS 7.4 on Dell servers. I'm running this command in a script: kill -SIGUSR2 ps -ef|grep ${rule}/etc/suricata/suricata.yaml|grep -v grep|awk '{ print $2 }' The ps part here grabs PID, but what does SIGUSR2 do? I see it's "user-defined"; how does that translate into actions?

I have a question. Studying processes management I observed a strange behavior, on a CentOS 7. I know that killing a parent process, the child processes are killed also. But not in the following case. I ran the command dd, just for example: [root@server2 ~]# dd if=/dev/zero of=/dev/null & 1756 [root@server2 ~]# ps fax | grep -B2 dd 1737 pts/2 S 0:00 \_ su - 1741 pts/2 S 0:00 \_ -bash 1756 pts/2 R 1:18 \_ dd if=/dev/zero of=/dev/null After that I tried to kill (with SIGKILL signal) the parent process, that is the bash, but this action doesn't kill the dd process: [root@server2 ~]# kill -9 1741 Killed [user@server2 ~]# The shell terminates but as you can see in the top command output, the dd process is still working: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 1756 root 20 0 107948 612 512 R 99.9 0.1 10:06.98 dd Do you have any idea about it please?

I am trying to write a script that kills service running at a specific port. This is my script: a=$(ps ax | grep 4990 | grep java | awk '{print $1}') kill -9 $a It's a java program. This script works sometimes, but mysteriously fails most of the time. Is there any other way to kill a service running on a port? My port is 4990.

(On OS X 10.11.3) I'm having a problem starting a java process that needs to listen on port 8040. Getting a BindException. So seems like somebody else is already listening on it. A quick check confirms that: lsof -i TCP| fgrep LISTEN | grep 8040 jspawnhel 13566 alon 255u IPv6 0x2a5edc8fe0a093d7 0t0 TCP *:8040 (LISTEN) jspawnhel 14482 alon 255u IPv6 0x2a5edc8fe0a093d7 0t0 TCP *:8040 (LISTEN) jspawnhel 81770 alon 255u IPv6 0x2a5edc8fe0a093d7 0t0 TCP *:8040 (LISTEN) So, I'm trying to figure out what these processes are, but I don't understand what ps is showing me: ps ax | grep "13566\|14482\|81770" 13566 ?? U 0:00.00 313:316 14482 ?? U 0:00.00 324:327 81770 ?? U 0:00.00 301:304 what does the "??" mean? what is 313:316 in this context? I can't kill it either, even with -9: kill -9 13566 ps ax | grep 13566 13566 ?? U 0:00.00 313:316 Tried many times... Any help is appreciated.

When I run podman container kill -a, I get can only kill running containers. 11d887d57069b3ee630fd6f1b13d600485c34f5020ff09fec65f4e31dd7242a5 is in state configured: container state improper can only kill running containers. 2132c0543eedbe3c4ee8680da508fea6251d38107d5e707f260eb5aa8549409d is in state configured: container state improper can only kill running containers. 2db317cc73ec92e434fda88653f872e4c4cf07e9f32c0c29ecc5e69515beb96d is in state exited: container state improper can only kill running containers. 465d133dec7a568bd8a6231036e1c489b6a6f88c65154629d75ce4161fb6e3c4 is in state exited: container state improper Subsequent runs still show the containers. How can I get rid of them?

I have a shell script running in the background, which runs 5 different jobs. When I run the shell script all 5 jobs start running in order. When I kill this shell, whichever process is running, will still continue to run, even though I have killed the shell. $ bash shell.sh & echo $! this gives me the PID of the shell, which allows me to kill it later if I wish to do so at some point. #!/bin/bash JOB1 JOB2 JOB3 JOB4 JOB5 How can I make the shell kill all process running within, once it has been killed?

I am familiar with kill command , and most of the time we just use kill -9 to kill a process forcefully, there are many other signals that can be used with kill. But I wonder what are the use cases of pkill and killall, if there is already a kill command. Do pkill and killall use the kill command in their implementation? I mean they are just wrappers over kill or they have their own implementation? I would also like to know how pgrep command gets the process id from the process name. Do all these commands use the same underlying system calls? Is there any difference from a performance point of view, which one is faster?

For example, if I ssh to the server at multiple office computer, how can I conveniently kill those ssh at home when I ssh to the server machine?

This is my bash script. All it does is to check whether a service has started and whether some processes are running as expected. It ends abruptly with a "Terminated" message. I tried debugging it with the set -x flag, and I still don't know what is going wrong. Stack Overflow and Google don't show me any other people with a similar problem. The script has permissions of 755. Some commands are obfuscated, for obvious reasons. #!/bin/bash set -x DAEMON_BIN=/etc/init.d/init-god DAEMON_BIN_START="${DAEMON_BIN} start" DAEMON_BIN_STOP="${DAEMON_BIN} stop" SOME_VARIABLE="foo" CHEF_CONFIG_FILE_PATH="/path/to/file" NODE_INFO_FILE="/mnt/node_info/properties" function get_key_value (){ value=$(grep -Po "(? /dev/null nohup pkill -f resque &> /dev/null eval $DAEMON_BIN_START sleep 15 PROCESS_COUNT=ps aux | awk '/[p]rocess-name/' | wc -l NODE_NAME=get_key_value node_name if [[ $NODE_NAME -eq $SOME_VARIABLE && $PROCESS_COUNT -eq 1 ]]; then echo "DAEMON and scheduler are running fine." ; else echo "A problem with DAEMON has occured." ; fi EXPECTED_PROCESS_COUNT=get_key_value no_of_workers ACTUAL_WORKER_COUNT=ps ax | grep [r]esque-[0-9] if [[ $EXPECTED_PROCESS_COUNT -eq $ACTUAL_WORKER_COUNT ]]; then echo "Correct Number of workers initialized." ; else echo "More workers exist than are permitted." ; fi for (( i=0; i<${EXPECTED_PROCESS_COUNT}; i++ )); do WORKER_NAME=get_key_value worker_${i} COUNT=ps ax | grep ${WORKER_NAME} | grep -v grep | wc -l if [[ $COUNT -eq 1 ]]; then #statements echo "${WORKER_NAME} is running." else echo "${WORKER_NAME} may not be running or might have more than 1 copies." fi done The debug output of the script is as follows: + DAEMON_BIN=/etc/init.d/init-god + DAEMON_BIN_START='/etc/init.d/init-god start' + DAEMON_BIN_STOP='/etc/init.d/init-god stop' + SOME_VARIABLE=foo + CHEF_CONFIG_FILE_PATH=/path/to/file + NODE_INFO_FILE=/mnt/node_info/properties + eval /etc/init.d/init-god stop ++ /etc/init.d/init-god stop . Stopped all watches Stopped god + nohup pkill DAEMON + nohup pkill -f resque Terminated Why does this script exit with a "Terminated" message? What should I do to prevent this from happening?

I have started a wget on remote machine in background using &. Suddenly it stops downloading. I want to terminate its process, then re-run the command. How can I terminate it? I haven't closed its shell window. But as you know it doesn't stop using Ctrl+C and Ctrl+Z.

Sometimes programs will lock up in the background and cause high CPU usage. Is there any way I can programmatically ascertain which process is causing the highest CPU load at the moment and kill it?

Given a | b, i'd like to kill b when a is finished. b is an interactive process, which doesn't terminates when a is finished (fzf in my case), and the whole a | b is executed in a $() subshell. So far what i come up with was echo $({ sleep 5 & a=$!; { wait $a; kill $b; } } | { fzf & b=$!; }) sleep represents a, and fzf represents b, the result in the example is used by echo, but in my case, it'd be an argument for ssh. It seems, that $b is not the PID of fzf, it's empty. As far as i understand, this shouldn't be the case, since i've used {}, and not (), so it's not executed in a subshell.