Job -l after nohup - linux

How can I monitor a job that is still running (I guess detached?) after I started it with nohup, exited the server and logged back in? Normally, I use jobs -l to see what's running, but this is showing blank.

You need to understand the difference between a process and a job. Jobs are managed by the shell, so when you end your terminal session and start a new one, you are now in a new instance of Bash with its own jobs table. You can't access jobs from the original shell but as the other answers have noted, you can still find and manipulate the processes that were started. For example:
$ nohup sleep 60 &
[1] 27767
# Our job is in the jobs table
$ jobs
[1]+ Running nohup sleep 60 &
# And this is the process we started
$ ps -p 27767
PID TTY TIME CMD
27767 pts/1 00:00:00 sleep
$ exit # and start a new session
# Now jobs returns nothing because the jobs table is empty
$ jobs
# But our process is still alive and kicking...
$ ps -p 27767
PID TTY TIME CMD
27767 pts/1 00:00:00 sleep
# Until we decide to kill it
$ kill 27767
# Now the process is gone
$ ps -p 27767
PID TTY TIME CMD

You can monitor if the proceses if still running using
ps -p <pid>, where is the ID of the process you get after using the nohup command.
If you see valid entries you process is probably alive.

You could have a list of the processes running under current user with ps -u "$USER" or ps -u "$(whoami)".

Try this :
ps -ef | grep <pid>

Related

Linux cannot kill a PID: invalid signal

IN ubuntu Amazon EC2 instances with root access
when do
ps -e
The process shows up with a valid PID and process name. The database table also suggests the process is still ongoing.
PID TTY TIME CMD
32194 ? 00:00:00 test
32253 ? 00:00:00 mysql
However, any of the following commands kill the process, but returns nothing or "invalid signal".
top
kill
Type in PID
y
returns "invalid signal"
or
kill -9 PID
kill -s PID
etc.
Could any guru enlighten how to deal with the "ghost jobs"?
Did you use the correct rights to kill the process? With root you should be able to kill the process using either:
$ su -
# kill -9 PID
or
$ sudo kill -9 PID
You have the id of the process, say 32194, I suggest you run:
pgrep -l a | grep 32194
If the process name has an 'a', the output will show the line and the process name. if not have an 'a', change the letter by other one.
When the process appear, just kill it with:
pkill <process name>

In unix I used kill command by providing a ppid then it close the terminal . why? kill -9 ppid

sleep 5000
In one terminal and in second terminal I'm running:
ps -ef | grep sleep
Then I'm killing this process in second terminal by using the ppid. Then it will close the first terminal where I run the sleep command. It will not create sleep command as an orphan.
$ ps -ef | grep sleep
trainee 4887 4864 0 17:05 pts/0 00:00:00 sleep 5000
trainee 4889 4264 0 17:05 pts/1 00:00:00 grep --color=auto sleep
kill -9 4864
Why?
Presumably the parent of the sleep is your shell. When you kill that your login is terminated and your terminal closes.
The Wikipedia article on Orphan process reads (in part),
An orphan process is a computer process whose parent process has finished or terminated, though it remains running itself.
and
A process can be orphaned unintentionally, such as when the parent process terminates or crashes. The process group mechanism in most Unix-like operation systems can be used to help protect against accidental orphaning, where in coordination with the user's shell will try to terminate all the child processes with the SIGHUP process signal, rather than letting them continue to run as orphans.

How to know if the process is set NOHUP?

Using jobs I know the process is running.
bash-4.2$ jobs
[1]+ Running test.sh &
I wanted it to be set NOHUP so that it won't be killed when I exit. I used
disown
and
bash-4.2$ jobs
shows nothing. I'm not sure if the process is set NOHUP or not. I'm curious about this because after I read the manual it says
disown -h
should be used to set NOHUP.
Edit
I don't think the link Find the Process run by nohup command helps. The question is different than that one.
I'm gonna restate my problem. I run a program without nohup, and later I wanted it to be set NOHUP so that it won't be killed when I exit the system. So I used disown, but later I found the manual says I should have used disown -h to set NOHUP. I want to check if my process is set NOHUP or not successfully. If not, what can I do to set it to be NOHUP?
UPDATE
I know two ways my be helpful:
1) Whenever a process is running over nohup It writes output on ~/nohup.out . So you can check this file by running command find -cmin 2. It shows you if nohup.out is changing each 2 seconds or not.
If it is changing you would understand that sth is running by nohup command, after that you can check it with lsof and continue your checking...
2) If you logout from specific user andgo to tty then do ps aux | grep <user> or ps aux | grep ? then you can understand that is running with nohup command... because there is no pts then it shows you ? instead...
useful command:
ps aux | grep <program> | awk -F" " '{print $7}'
Hope to be helpful

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] .

How to get a list of programs running with nohup

I am accessing a server running CentOS (linux distribution) with an SSH connection.
Since I can't always stay logged in, I use "nohup [command] &" to run my programs.
I couldn't find how to get a list of all the programs I started using nohup.
"jobs" only works out before I log out. After that, if I log back again, the jobs command shows me nothing, but I can see in my log files that my programs are still running.
Is there a way to get a list of all the programs that I started using "nohup" ?
When I started with $ nohup storm dev-zookeper ,
METHOD1 : using jobs,
prayagupd#prayagupd:/home/vmfest# jobs -l
[1]+ 11129 Running nohup ~/bin/storm/bin/storm dev-zookeeper &
NOTE: jobs shows nohup processes only on the same terminal session where nohup was started. If you close the terminal session or try on new session it won't show the nohup processes. Prefer METHOD2
METHOD2 : using ps command.
$ ps xw
PID TTY STAT TIME COMMAND
1031 tty1 Ss+ 0:00 /sbin/getty -8 38400 tty1
10582 ? S 0:01 [kworker/0:0]
10826 ? Sl 0:18 java -server -Dstorm.options= -Dstorm.home=/root/bin/storm -Djava.library.path=/usr/local/lib:/opt/local/lib:/usr/lib -Dsto
10853 ? Ss 0:00 sshd: vmfest [priv]
TTY column with ? => nohup running programs.
Description
TTY column = the terminal associated with the process
STAT column = state of a process
S = interruptible sleep (waiting for an event to complete)
l = is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
Reference
$ man ps # then search /PROCESS STATE CODES
Instead of nohup, you should use screen. It achieves the same result - your commands are running "detached". However, you can resume screen sessions and get back into their "hidden" terminal and see recent progress inside that terminal.
screen has a lot of options. Most often I use these:
To start first screen session or to take over of most recent detached one:
screen -Rd
To detach from current session: Ctrl+ACtrl+D
You can also start multiple screens - read the docs.
If you have standart output redirect to "nohup.out" just see who use this file
lsof | grep nohup.out
You cannot exactly get a list of commands started with nohup but you can see them along with your other processes by using the command ps x. Commands started with nohup will have a question mark in the TTY column.
You can also just use the top command and your user ID will indicate the jobs running and the their times.
$ top
(this will show all running jobs)
$ top -U [user ID]
(This will show jobs that are specific for the user ID)
sudo lsof | grep nohup.out | awk '{print $2}' | sort -u | while read i; do ps -o args= $i; done
returns all processes that use the nohup.out file

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