How to kill a shell script and processes it created? - linux

I run a shell script inside php (using shell_exec). I want to kill it and all processes it created when it is in operation. I know the shell script pid. Do you have any suggestion?
I am using ubuntu, php as apache module.
Thank you.
Example:
#!/bin/bash
echo hello
sleep 20
When I kill my script (shell_exec("sudo kill -9 $pid")), the sleep process is not killed which is not desired.

use
pkill -TERM -P pid
will kill the child processes
see this answer

Use this kill command instead:
kill -- -$pid
to kill the running script and all its spawned children.

Related

Kill all sleep processes

How do I kill all sleep processes that are running? I realize that I can either use the kill command to kill each process via its PID, or I can use pkill to kill the sleep command by name. I'm trying to figure out how I would do this, any help would be appreciated. I used
man pkill
to get some help but am still unsure.
If you really must do this dangerous action, use the killall command:
killall sleep
There is an option for the pkill command that will kill all processes named the given pattern.
pkill -x [pattern] (or) pkill -exact [pattern]
These commands will kill all processes with the same name as [pattern]

How to get the process ID to kill a nohup process?

I'm running a nohup process on the server. When I try to kill it my putty console closes instead.
this is how I try to find the process ID:
ps -ef |grep nohup
this is the command to kill
kill -9 1787 787
When using nohup and you put the task in the background, the background operator (&) will give you the PID at the command prompt. If your plan is to manually manage the process, you can save that PID and use it later to kill the process if needed, via kill PID or kill -9 PID (if you need to force kill). Alternatively, you can find the PID later on by ps -ef | grep "command name" and locate the PID from there. Note that nohup keyword/command itself does not appear in the ps output for the command in question.
If you use a script, you could do something like this in the script:
nohup my_command > my.log 2>&1 &
echo $! > save_pid.txt
This will run my_command saving all output into my.log (in a script, $! represents the PID of the last process executed). The 2 is the file descriptor for standard error (stderr) and 2>&1 tells the shell to route standard error output to the standard output (file descriptor 1). It requires &1 so that the shell knows it's a file descriptor in that context instead of just a file named 1. The 2>&1 is needed to capture any error messages that normally are written to standard error into our my.log file (which is coming from standard output). See I/O Redirection for more details on handling I/O redirection with the shell.
If the command sends output on a regular basis, you can check the output occasionally with tail my.log, or if you want to follow it "live" you can use tail -f my.log. Finally, if you need to kill the process, you can do it via:
kill -9 `cat save_pid.txt`
rm save_pid.txt
I am using red hat linux on a VPS server (and via SSH - putty), for me the following worked:
First, you list all the running processes:
ps -ef
Then in the first column you find your user name; I found it the following three times:
One was the SSH connection
The second was an FTP connection
The last one was the nohup process
Then in the second column you can find the PID of the nohup process and you only type:
kill PID
(replacing the PID with the nohup process's PID of course)
And that is it!
I hope this answer will be useful for someone I'm also very new to bash and SSH, but found 95% of the knowledge I need here :)
suppose i am running ruby script in the background with below command
nohup ruby script.rb &
then i can get the pid of above background process by specifying command name. In my case command is ruby.
ps -ef | grep ruby
output
ubuntu 25938 25742 0 05:16 pts/0 00:00:00 ruby test.rb
Now you can easily kill the process by using kill command
kill 25938
jobs -l should give you the pid for the list of nohup processes.
kill (-9) them gently.
;)
You could try
kill -9 `pgrep [command name]`
Suppose you are executing a java program with nohup you can get java process id by
`ps aux | grep java`
output
xxxxx 9643 0.0 0.0 14232 968 pts/2
then you can kill the process by typing
sudo kill 9643
or lets say that you need to kill all the java processes then just use
sudo killall java
this command kills all the java processes. you can use this with process. just give the process name at the end of the command
sudo killall {processName}
If your application always uses the same port, you can kill all the processes in that port like this.
kill -9 $(lsof -t -i:8080)
This works in Ubuntu
Type this to find out the PID
ps aux | grep java
All the running process regarding to java will be shown
In my case is
johnjoe 3315 9.1 4.0 1465240 335728 ? Sl 09:42 3:19 java -jar batch.jar
Now kill it kill -9 3315
The zombie process finally stopped.
when you create a job in nohup it will tell you the process ID !
nohup sh test.sh &
the output will show you the process ID like
25013
you can kill it then :
kill 25013
I started django server with the following command.
nohup manage.py runserver <localhost:port>
This works on CentOS:
:~ ns$netstat -ntlp
:~ ns$kill -9 PID
This works for mi fine on mac
kill -9 `ps -ef | awk '/nohup/{ print \$2 }'`
I often do this way. Try this way :
ps aux | grep script_Name
Here, script_Name could be any script/file run by nohup.
This command gets you a process ID. Then use this command below to kill the script running on nohup.
kill -9 1787 787
Here, 1787 and 787 are Process ID as mentioned in the question as an example.
This should do what was intended in the question.
If you are unaware of the PID, then first find it using TOP command
top -U userid
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
You will get the PID using top, then perform the kill operation.
$ kill -9 <PID>
Today I met the same problem. And since it was a long time ago, I totally forgot which command I used and when. I tried three methods:
Using the STIME shown in ps -ef command. This shows the time you start your process, and it's very likely that you nohup you command just before you close ssh(depends on you) . Unfortunately I don't think the latest command is the command I run using nohup, so this doesn't work for me.
Second is the PPID, also shown in ps -ef command. It means Parent Process ID, the ID of process that creates the process. The ppid is 1 in ubuntu for process that using nohup to run. Then you can use ps --ppid "1" to get the list, and check TIME(the total CPU time your process use) or CMD to find the process's PID.
Use lsof -i:port if the process occupy some ports, and you will get the command. Then just like the answer above, use ps -ef | grep command and you will get the PID.
Once you find the PID of the process, then can use kill pid to terminal the process.
About losing your putty: often the ps ... | awk/grep/perl/... process gets matched, too! So the old school trick is like this
ps -ef | grep -i [n]ohup
That way the regex search doesn't match the regex search process!
if you are on a remote server, check memory usage with top , and find your process and its ID. After that, just execute kill [your process ID] .

Shell Script for Killing PID

I run a few processes that I created myself on my Ubuntu Server, and to kill them I run:
sudo fuser -n tcp PORT
kill -9 PID-DISPLAYED
Is there any way I can obtain the PID from a port using a shell script, then kill it by running the shell script.
Thanks.
fuser can kill it:
-k, --kill
Kill processes accessing the file. Unless changed
with -SIGNAL, SIGKILL is sent. An fuser process
never kills itself, but may kill other fuser processes.
The effective user ID of the process executing fuser is
set to its real user ID before attempting to kill.
Try using either killall, or pkill, either of which will close all processes of the type of argument you describe, for example:
killall firefox
Will kill all running instances of firefox.
See
this link of pkill.

Suspending a bash script running in the background

I have a bash script running in the background, and it executes in a loop every 5 seconds. This effects the commands that are being executed at the shell itself.
Is there a way, i can suspend the script execution until the shell is not executing other commands.
thanks
to stop the scipt you can use
kill -s STOP $PID
where $PID contains the process ID of the script. To start it again, you use
kill -s CONT $PID
Renice should help in such scenario.
Using renice you can decrease/increase the priority of the process.
Look man page for more detailed help.

How to run a program and know its PID in Linux?

How to run a program and know its PID in Linux?
If I have several shells running each other, will they all have separate PIDs?
Greg's wiki to the rescue:
$! is the PID of the last backgrounded process.
kill -0 $PID checks whether $PID is still running. Only use this for processes started by the current process or its descendants, otherwise the PID could have been recycled.
wait waits for all children to exit before continuing.
Actually, just read the link - It's all there (and more).
$$ is the PID of the current shell.
And yes, each shell will have its own PID (unless it's some homebrewed shell which doesn't fork to create a "new" shell).
1) There is a variable for that, often $$:
edd#max:~$ echo $$ # shell itself
20559
edd#max:~$ bash -c 'echo $$' # new shell with different PID
19284
edd#max:~$ bash -c 'echo $$' # dito
19382
edd#max:~$
2) Yes they do, the OS / kernel does that for you.
the top command in linux(Ubuntu) shows the memory usage of all running programs in linux with their pid. Kill pid can kill the process.

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