How do I kill a command that I am running in background

baronobeefdip · 07-21-2014, 09:18 PM

I have installed raspian and I have been running commands and processes in the background via ssh. I want to be able to SSH back into the pi and kill the process I told it to run in the background so I can start a new one. Some of the typical methods found on google searches don't work but I am open so suggestions.

szboardstretcher · 07-21-2014, 09:26 PM

So ssh back into the pi and kill the process. Use pgrep or ps to find its pid number and use kill or pkill to kill the process.

If you mean you want to keep track of the pid of background processes you create to later kill them without having to look them up, you will have to make your own pid file:

Code:

> your_pids          # clear pid file
your_command &       # run command in background
echo $! >> your_pids # print pid to file

Then when you want to kill all your background processes you created

Code:

while read line
do
    pkill $line
    echo "Killed process $line"
done < your_pids

evo2 · 07-21-2014, 09:28 PM

Hi,

Quote:

Originally Posted by baronobeefdip

I have installed raspian and I have been running commands and processes in the background via ssh. I want to be able to SSH back into the pi and kill the process I told it to run in the background so I can start a new one.

That should be possible.

Quote:

Some of the typical methods found on google searches don't work but I am open so suggestions.

I could list some typical methods, but presumably the "don't work", so it is best you tell us what you tried and what happened.

Evo2.

baronobeefdip · 07-22-2014, 09:26 AM

Raspbian is very strange, in saying that many if the basic commands found in a typical Debian and Ubuntu installation are absent (I guess that was done to preserve space on the SD card). I can't run a command like nslookup, and traceroute. What was really getting to be was the absence of the jobs command. I want to be able to bring the process back to the foreground but I am unable to do that because the jobs command isn't present on the operating system. What package do I need to install in order to have the command. basically speaking, the jobs command wasn't present in the PI, How do I get it installed in the pi because I don't know what aptitude installation I should run in order to get it going on the pi.

273 · 07-22-2014, 04:27 PM

Jobs appears to be working just fine on my Pi -- which version of Raspbian are you using? You say you're SSHing into the Pi then exiting and going back -- surely that will loose track of your running processes? If you just want to return to the same terminal session that you left when you disconnected know the Pi you may want to use screen on the Pi.

evo2 · 07-22-2014, 08:20 PM

Hi,

jobs is a shell builtin. What shell are you using? If some programs that you want are missing just go ahead and "apt-get install" them.

Evo2.

baronobeefdip · 07-23-2014, 01:47 AM

I'm in bash, I run the jobs command and nothing displays.

273 · 07-23-2014, 02:01 AM

Quote:

Originally Posted by baronobeefdip

I'm in bash, I run the jobs command and nothing displays.

As far as I am aware that is normal behaviour for jobs -- once you disconnect your session you lose your jobs list. As I mentioned one way around this is to use screen (I hear tmux may be better though) and return to a session.

evo2 · 07-23-2014, 02:06 AM

Hi,

Quote:

Originally Posted by baronobeefdip

I'm in bash, I run the jobs command and nothing displays.

really? To demonstrate, please run the following and post the output.

Code:

nano &
jobs

Evo2.

baronobeefdip · 07-24-2014, 09:26 PM

Here is the output

Code:

root@raspberrypi:~# nano &
[1] 2611
root@raspberrypi:~# jobs
[1]+  Stopped                 nano
root@raspberrypi:~#

evo2 · 07-24-2014, 09:57 PM

Hi,

Quote:

Originally Posted by baronobeefdip

Here is the output

Code:

root@raspberrypi:~# nano &
[1] 2611
root@raspberrypi:~# jobs
[1]+  Stopped                 nano
root@raspberrypi:~#

Ok, so that works as expected. Can you post something that demonstrates the problem?

Evo2.