A process is an instance of a computer program that is being executed.

learn more… | top users | synonyms (1)

30
votes
1answer
1k views

What is a “subreaper” process?

The word "subreaper" is used in some answers. Searching Google also turn up entries where the word is "just used". How can I understand what a "subreaper" is?
1
vote
1answer
29 views

Find the command the application has spawned

Is there a way to find the command by which an application has launched an external process? Motivation: I'm using an IDE Qt Creators which at some point calls a SFTP to transfer a file to a remote ...
0
votes
1answer
35 views

strace vs web browser

I was trying to strace an iceweasel like this: strace -e trace=connect iceweasel And I was expecting to see calls to connect when I load new pages. Surprisingly, there weren't any. Why so? Am I ...
0
votes
1answer
76 views

which process was running on a particular time in linux [duplicate]

Is there any way to find which process was running on a particular time in linux? I found the disk utilization was 99% and CPU utilization was 100% on two different times yesterday. The issue was ...
2
votes
1answer
119 views

Why do I have 9 bash processes, why does one of them take up so much CPU and how do I stop them?

I have 9 different bash processes running at all times (I sometimes get more, for example, I have 37 bash processes now.). I found this question, where OP had a similar issue. But I don't see this as ...
0
votes
1answer
37 views

Help with the PS and TTY?

I have this question for you guys: I execute on a different shell 'sleep 600'. I open a different terminal and I executed 'ps' to see my current process , however , I dint see any sleep process. I ...
0
votes
0answers
29 views

Supervisord fails to run a program

I've a program that I try to run with supervisord but keep failing. The following is supervisord configuration: $ cat /etc/supervisor/conf.d/application.conf [program:application-web-1] command=env ...
-1
votes
3answers
33 views

Output of processes and specific users with adding some text

I have tried to output processes for specific user but with adding some text. I can do like it is described in this answer How to see process created by specific user in Unix/linux but I don't know ...
0
votes
0answers
22 views

High CPU usage after Version Upgrade

Not sure if is related to the version upgrade but since I have updated my Raspberry to Linux version 4.1.13+ (dc4@dc4-XPS13-9333) (gcc version 4.8.3 20140303 (prerelease) (crosstool-NG ...
2
votes
1answer
263 views

iotop showing 1.5 MB/s of disk write, but all programs have 0.00 B/s

I don't understand iotop output: it shows ~1.5 MB/s of disk write (top right), but all programs have 0.00 B/s. Why? The video was taken as I was deleting the content of a folder with a few millions ...
3
votes
2answers
226 views

Content of /proc/<PID>/cmdline file depends on script shebang?

I have a bash script named test.sh which I start with startproc. In case I use #!/usr/bin/env bash shebang in test.sh, the /proc/<PID>/cmdline file looks following: SERVER:~ # cat ...
0
votes
2answers
116 views

Shell script to kill processes except those owned by user

I am Looking for some help in creating a script to kill processes, but return an error message if they are owned by root. Firstly I would like to say that I am a total beginner at this. At the moment ...
1
vote
1answer
82 views

Kill process on specific port

It has been asked before but how to do it with OpenBSD? I tried some different method but none worked. $ sudo fuser -k 80/tcp fuser: 80/tcp: No such file or directory $ kill $(sudo lsof -t -i:80) ...
0
votes
3answers
264 views

How to kill a command executed from a script?

I would like to start a tcpdump in my own script an after some time I would like to kill it again. How can I access the PID from the tcpdump. I tried it with $$ , but this only kills the script. if ...
2
votes
2answers
79 views

How to kill line of PID?

I have process which created multiple PID's. I want to kill all those PID's. I have tried pkill <process_name>. But PID not getting killed as they were wait to resource releasing. I have ...
1
vote
1answer
68 views

Is it possible to rename a process you own from outside that process?

If I'm logged in as $USER, and I run top and I can see a process I own can I rename that process? If so, how? If not, can root rename a foreign process? If so, how? If not, why?
3
votes
1answer
166 views

Long-running R script is getting killed automatically

I'm attempting to run an experiment for my masters thesis that involves an R script that has to run for quite a while (up to 24 hours of 100% cpu usage). It's a single-core process, and as far as I ...
1
vote
0answers
16 views

How does an OS detect an access to random memory address of a compiled program? [duplicate]

I've read a couple things about memory management/virtual memory and I need a little more details on one important point. If I compile a program and it does an access to a hard-coded address without ...
3
votes
2answers
41 views

How to find what processes run by the user right now?

Once again, I'm a beginner and I can't find the right command. I want to view the processes that I'm currently running.
2
votes
1answer
88 views

Ubuntu: Process vfs-worker taking all CPU resources

My Cloud9 (Ubuntu-based cloud IDE) began to be unresponsive after I tried to save some files (they didn't save to my cloud workspace). It shows 100% CPU utilization and a process that takes all CPU ...
1
vote
0answers
30 views

What is the best practice for setting a process niceness?

I have an agent which runs on my customer's hosts. I want this agent to leave the smallest possible footprint on their hosts, that is, I don't want to degrade my customers' performance. My agent runs ...
1
vote
2answers
79 views

screen process in capitals

I've noticed that when running screen the process identified with it actually shows up in capitals. Linux Debian Wheezy. Here an example with me ssh'in into a machine, running screen -S test and ...
15
votes
1answer
869 views

Why can I list other users processes without root permission?

Using ps -aux or top, I can list other users running processes, but i'm neither running as root or making use of sudo, why ?
1
vote
1answer
68 views

How are piped processes presented in ps output?

I have a following very simple script which watches /tmp directory for new files and output of inotifywait is piped to sed: #!/bin/bash /usr/local/bin/inotifywait -q -m /tmp --format %f | sed ...
0
votes
1answer
42 views

Write a process with 0 idle memory [closed]

I see that the daemons in my PC's process list idle with 0 memory usage. I want my daemons to run like that, so how is it done?
6
votes
1answer
164 views

Replace current process by its coprocess/child

I have a program P that expects to receive "Hello" and output "Why?" before providing a feature. This feature is used by other programs that are not aware that it is common courtesy to start a ...
1
vote
0answers
28 views

i3pystatus-python process blocks suspend and shutdown

After using my arch-linux system a decent time, it can happen, that the i3pystatus process is not freezable anymore. As a result I can't suspend my laptop anymore. Killing the process (killall -9 ...
2
votes
1answer
34 views

Find process that stalls apache

I'm programming a PHP web page and I started seeing some strange behavior on my computer, at some point apache / php takes to long to show the webpage on the browser (8 secs), first i thought it was ...
0
votes
1answer
78 views

history/log of command-lines executed to launch processes(pid) [duplicate]

Given a certain PID, is it possible to discover what command-line executed this process? top, atop, ps provide real time informations, I'm looking for something whereby I can look the past, because ...
4
votes
4answers
240 views

Does a service restart send a HUP?

I have noticed that doing a service restart with something like: service sshd restart is very similar to doing something like: pkill -HUP sshd However the pkill would close my ssh session where ...
2
votes
1answer
43 views

How does kill by pgid affect new subprocesses?

I have a very complicated application, which has its init-script and main service runs as a daemon. I want to stop it fast and gracefully, so I used this in stop() function: group_id=$(ps -o pgid= ...
5
votes
2answers
120 views

Why process does not (seem to) exist before fifo read

I have a trivial Python script: #!/usr/bin/python import os, sys sys.stderr.write('I am %s' % os.getpid()) sys.stderr.flush() print "hello" sys.stderr.write('I am done') When I run this script ...
2
votes
3answers
551 views

bash - get pid for a script using the script filename

I have two scripts: running_script script_one I need to get the PID for the/any instances of running_script running under a username, and then pkill to stop the running_script and daughter ...
2
votes
1answer
58 views

how to get processor that thread is currently assigned to?

I've found such column in ps -elF: PSR processor that process is currently assigned to. I need something similar but for threads. ps huH p 1234 prints threads of process 1234, can I somehow add ...
3
votes
3answers
111 views

How to get the pid to the last background app

Following from this question: How to get the pid of the last executed command in shell script? The thread there is good and clear, but what if the command actually doesn't require a '&' at the ...
2
votes
2answers
84 views

How to get information about files being copied to my machine by remote rsync command?

I am rsyncing a directory from machine B to machine A. rsync command is run on machine B. On machine A, what kind of information can I get about this rsync process (progress/amount of data downloaded ...
2
votes
3answers
87 views

How to make init script print “OK” only when all subprocesses are stopped?

I have a very complex python application. It has it's own init script, but when I execute: sudo service my_service_daemon stop It prints "Stopping my_service_daemon [OK]", but in real ...
1
vote
2answers
61 views

How to monitor the output as the process runs on a RedHat Linux server?

You need to run a process on a RedHat Linux server that takes a little while to run. You want to monitor the output as the process runs but need to guarantee that the process won't terminate if you ...
2
votes
1answer
49 views

Strange behavior of 'ps -o pgid'

Intro: I have a daemon, which spawn processes and I have to stop it all gracefully. The solution I found on web based on pgid: group_id=$(ps -o pgid= $(cat $pidfile)) if [ ! -z $group_id ]; then ...
1
vote
1answer
88 views

Security - Runing Daemon, program as root or user vs sudo su

I have some questions about Linux security: Running a process as root is a big mistake (root has too much power + a program get too much permissions in the system). I always ran processes as a user ...
1
vote
1answer
295 views

How to get UID and PID

So here's what I want to do: User inputs a USERNAME. Based on this username, I need to get the list of processes started by this user. I am planning to do this by getting the UID of this user and ...
1
vote
0answers
67 views

CentOS Running process not responding to kill signals and not context switched

An updatedb process on my linux server is not responding to kill signals. (kill -9 or SIGSTOP) [root@chroot-1 ~]# ps auwx | grep -i 4505 root 4505 99.5 0.0 59544 1256 ? RN 09:43 ...
5
votes
1answer
107 views

PID in arch-chroot is incorrect

I am trying to run a python script in a chroot (specifically, the chroot is created with arch-chroot). The python script relies on os.getpid(), but this seems to be returning an incorrect PID within ...
1
vote
1answer
165 views

pid file error when starting stunnel

I'm trying to start stunnel at my mac os as client. But I'm not able to get it running as I have noticed this reported problem at the stunnel's log file: 2015.10.10 16:10:24 LOG5[ui]: stunnel 5.23 on ...
2
votes
2answers
406 views

linux equivalent to AIX proctree command to show all child and parent processes of a given PID

Sometimes I'm looking for an equivalent for the AIX proctree command which displays all children and all ancestors of a specified PID and can be sometimes quite useful for troubleshooting purposes. As ...
1
vote
2answers
101 views

Which user is running the most processes?

My top looks like this: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 6524 asjzdiwq 30 10 500m 41m 24m S 0.0 0.3 0:15.27 php-cgi 21274 asjzdiwq 30 ...
1
vote
2answers
487 views

How to find PID of a while loop?

I run this command in Bash terminal while [ 0 ]; do i=1; echo $i; done Before running this loop, in another tab of gnome-terminal I did $ps aux | wc -l 192 While the loop is still ...
1
vote
1answer
163 views

pkill with regex

I have few java processes running like below, java -jar /my/path/to/app/myapp.jar java -jar /my/path/to/app/prodapp.jar java -jar /my/path/to/app/testapp.jar java -jar ...
2
votes
1answer
308 views

Why does a “child” process finish before its parent?

This is the code example given: # include <stdio.h> # include <unistd.h> void main() { static char *mesg[] = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}; int display(char ...
3
votes
3answers
542 views

How to create a process tree?

I have some code that kills processes and their children/grandchildren. I want to test this code. Currently I'm doing $ watch date > date.txt, which creates a process with a child. Is there any ...