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

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Is it possible to get process group ID from /proc?

In "http://stackoverflow.com/questions/13038143/how-to-get-pids-in-one-process-group-in-linux-os" I see all answers mentioning ps and none mentioning /proc. "ps" seems to be not very portable ...
1
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2answers
75 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 ...
9
votes
1answer
5k views

Real time processes scheduling in Linux

I have been learning some scheduling concepts. Currently my understanding so far is as below. There are real time processes and non real time processes. Non real time processes can have nice values ...
1
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3answers
129 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 ...
1
vote
1answer
43 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) ...
27
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4answers
38k views

How to view the output of a running process in another bash session?

I have left a script running on a remote machine from when I was locally working at it. I can connect over SSH to the machine as the same user and see the script running in ps. $ ps aux | grep ...
2
votes
2answers
889 views

How to use pgrep inside bash script correctly?

I'm running a GUI program called zeal(compiled from src) and add a script(zeal.sh) for the executable: #!/bin/bash if pgrep zeal &>/dev/null; then printf "already on\n" else ...
10
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5answers
3k views

Process descendants

I'm trying to build a process container. The container will trigger other programs. For example - a bash script that launches running background tasks with '&' usage. The important feature I'm ...
1
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1answer
35 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?
2
votes
2answers
61 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 ...
3
votes
1answer
86 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
15 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 ...
2
votes
1answer
44 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
25 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
54 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 ...
3
votes
2answers
1k views

A tee >( process ) is truncating its stdout when writing a file

When I use tee to pipe stdout directly to a "specific block of code" (which then writes the modified data to a file), I always get the full complement of exptected output lines in the file. ...
14
votes
1answer
742 views

Why can I list other users process without root permission?

Using ps -aux or top, I can list other users running process, but i'm neither running as root or making use of sudo, why ?
5
votes
2answers
73 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 ...
6
votes
1answer
142 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
1answer
46 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 ...
15
votes
7answers
6k views

Process Monitor equivalent for Linux?

Is there a Unix/Linux equivalent of Process Monitor, whether GUI or CUI? If it makes a difference, I'm looking at Ubuntu, but if there's an equivalent for other systems (Mac, other Linux variants ...
1
vote
1answer
36 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?
111
votes
7answers
66k views

Keep SSH Sessions running after disconnection

I sometimes have long running processes that I want to kick off before going home, so I create a SSH session to the server to start the process, but then I want to close my laptop and go home and ...
1
vote
0answers
20 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 ...
4
votes
2answers
2k views

What's the difference between lsof and fuser -uvm

Both shows the number of files we're using. Yet they both shows different results. root@host [~]# lsof /home4 root@host [~]# lsof /home2 root@host [~]# lsof /home4 Then we got fuser -uvm /home4 ...
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0answers
14 views

Error Disk 1:0 Thu 5 01:03:13 SAST 2015 [closed]

Everytime I use the su I get this error message : Error Disk 1:0 Thu 5 01:03:13 SAST 2015 This is the assignment given to me by my boss to figure it out and I have tried everything but cant seem ...
16
votes
7answers
6k views

What is using this network socket?

I'm trying to use NTP to update the time on my machine. However, it gives me an error: host # ntpdate ntp1.example.org 10 Aug 12:38:50 ntpdate[7696]: the NTP socket is in use, exiting What does the ...
2
votes
3answers
7k views

How to tell who is connected via vnc to my machine?

How do I check how many vnc connections or different users are currently connected to my machine? Only through wireshark? And how do I kill any other users connected through vnc?
6
votes
3answers
2k views

Alert when running process finishes

There are a few questions and answers on here with regard to being alerted when a process completes/exits(1, 2) – but these all assume that the user has issued said process themselves, and thus can ...
3
votes
2answers
93 views

What information about a process is retrievable after it is terminated?

After a process has been terminated, is it possible to retrieve any information about it, such as when it started and finished, &c. Is it possible to enable logging of this information?
0
votes
1answer
52 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
158 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 ...
1
vote
1answer
361 views

How to demonstrate invalid PID assumptions?

It seems many programmers are happy with saving a PID to a file, and then later read and use the PID as if it was guaranteed to be the same process. It seems the general idea is that the odds are good ...
2
votes
3answers
59 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 ...
2
votes
1answer
26 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= ...
2
votes
1answer
104 views

Process startup after boot

I know the following are ways processes get started in Linux from init.d (or similar) from shell (by user) forked by a running native daemon Is it ever possible on Linux for a process to be ...
2
votes
1answer
43 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 ...
2
votes
3answers
204 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 ...
127
votes
7answers
106k views

How can I close a terminal without killing the command running in it?

Sometimes I want to start a process and forget about it. If I start it from the command line, like this: redshift I can't close the terminal, or it will kill the process. Can I run a command in ...
14
votes
2answers
11k views

How to know reason of a process going to sleep state and wake it up?

When I do 'top' , I see my perl script process in 'S' state. Is there a way to know, what is making this perl process go in sleep state and ways to wake it up? Any way to debug to give more insights ...
3
votes
3answers
74 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 ...
1
vote
2answers
37 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
2answers
69 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 ...
3
votes
2answers
935 views

wait does not wait

If i have a file called myprogram containing sleep 200 date Run this in the background: $ sh myprogram & i want to know when myprogram has completed by using wait command $ cat >notify ...
2
votes
1answer
29 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 ...
3
votes
1answer
294 views

How can I know thread names that run on specific core

I am working in Java code. My code makes specific Java threads run on specific cores. In this code, I give names to Java threads. I need a Linux command that enables me to know the threads' names that ...
2
votes
0answers
52 views

Find which process is being joined by another?

If I have opened Nautilus and spawned a new Nautilus instance, a new PID is created for the new Nautilus instance. Shortly after, the instance is joined with the main Nautilus program running. Main ...
3
votes
4answers
63 views

Who forks the processes of piped commands in the shell?

Consider this command in the shell : ls|less Now we know that ls and less are run as two different processes. We know that the shell forks and creates a child process which load the ls program using ...
1
vote
3answers
108 views

What is the output of “du” command during a long copy?

Recently, I launched the cp command to create a backup of a big directory. So, I used a command like this: cp -rv big_directory new_location Because the files are big, it took a long time to ...
1
vote
1answer
35 views

Which process group does my program belong to when started from bash?

If I run a program from bash, then does my program belong to the same process group as the shell, or does it belong to a new process group? As I am making a shell in C, I need to handle the SIGINT ...