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

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3
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189 views

How to update user/group settings of a running process?

Suppose I change some user settings like its initial login group or add it to a new group. I now can do su user and work with these new settings. But all the previously running processes will still ...
2
votes
3answers
11k views

How to restart (or reset) a running process in linux

I have two Linux systems communicating over sockets (Desktop and ARM-based development board). I want to restart (or reset) my client application (running on a development board) when server sends a ...
4
votes
1answer
496 views

what does it mean 'fork()' will copy address space of original process

I'm studying 'operation system concepts' on my own and I'm studying the chp3. process part. There is an example where the 'fork()' function is called and depending of the returned pid value like the ...
0
votes
2answers
180 views

Why do some processes end with the letter “d”? [duplicate]

Some Linux binaries end with a "d", for example sshd, httpd, ppd, etc. Why is this so?
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0answers
36 views

If processes can't modify their parent's environment, what is MC doing?

As far as I know, a process cannot modify its parent's environment. However, when I run mc (GNU's Midnight Commander, a curses-based file manager) and then quit it, I end up with another $PWD: ...
3
votes
4answers
127 views

How do I get the value of a named option of an already running process in Linux?

I run the following command. ps -e -o args | grep destiny | grep UNIX I receive the following output. /path/to/destiny -r -m UNIX -t TCP -p 1501 What command can I use the get the value of the ...
1
vote
1answer
102 views

Systemcrash suexec forkbomb.sh ulimits

I got this script named fork.sh: #!/bin/sh forkbomb() { forkbomb | forkbomb & } ; forkbomb If I call it through suexec my whole system will consume 99% cpu. To prevent a normal bash forkbomb I ...
7
votes
3answers
2k views

How do Linux permissions work when a process is running as a specific group?

This is something I haven't been able to find much info on so any help would be appreciated. My understanding is thus. Take the following file: -rw-r----- 1 root adm 69524 May 21 17:31 ...
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0answers
30 views

Is there any considerations I should take when running untrusted apps as non-root user?

I have to use an application I don't trust (unstable) and I will run it as a non-privileged user so if something bad happens the damage would be limited to the home folder of that user. I removed ...
3
votes
1answer
52 views

Get all files open for writing with pid, recursively

Given a pid, I can get all the files open for writing something like: lsof -p 28827 | awk '$4 ~ "[wW]"{print $(NF-1), $NF}' One of those ends up being a pipe: 28827 232611 pipe I want to look-up ...
7
votes
1answer
281 views

How to enable random PIDs on Linux?

I'm currently comparing random PID implementation on OpenBSD, FreeBSD and Linux from security perspective. As long as OpenBSD and FreeBSD are concerned, my work is done. However, while the answer ...
0
votes
2answers
55 views

Is there a need to get rid of a zombie process? [duplicate]

I read somewhere (forgot where) that a zombie process continues to consume the process table entry (concretely the process identifier or PID), and causes a resource leak. Is it correct that a zombie ...
5
votes
4answers
778 views

Are the states of processes which are ready and scheduled to wait “S”?

In the output of top, the state S means interruptible sleep. What is the state of those processes which are scheduled to be ready and waiting for execution in CPU by the scheduler? Is it S or ...
3
votes
4answers
749 views

How to get the PID of a sub process across to the parent process in a bash shell script?

My shell script is as following: #!/bin/bash ./process1 #It will create a sub process: sub_process1 while [ condition ]; do break done kill -9 process1 and sub_process1 In my script, it will ...
6
votes
2answers
281 views

What to do when “nice” isn't good enough (FreeBSD)

I've been using x265 to encode some video on my workstation lately, but I have a problem: even though I launch it using nice -n 20 x265 to deprioritize it, it still slows the computer to a crawl while ...
14
votes
4answers
4k views

Run multiple commands and kill them as one in bash

I want to run multiple commands (processes) on a single shell. All of them have own continuous output and don't stop. Running them in the background breaks Ctrl-C. I would like to run them as a single ...
2
votes
0answers
32 views

Identify process

Every couple of minutes my Mac OSX machine starts running a process that consumes 10% of the CPU. It runs for a couple of seconds and then stops. I can see the process coming up in 'Top', but the name ...
4
votes
0answers
106 views

Is it possible to make an exec call that “returns”?

Is there a way to make the exec system call work like a function call that returns instead of totally replacing the current process image? My motivation is trying to integrate two shells with ...
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0answers
145 views

Create tree of processes

I'm implementing pstree as an assignment, and I would like to create test tree of processes, but I'm struggling to do so. I tried to do something like this to create tree of background processes ...
0
votes
1answer
40 views

Killall processes under a user?

So, I know you can pkill -U <uid>, but whenever I've used this, my entire system crashes. Further investigation shows it probably is because I'm not matching anything, so it matches everything? ...
0
votes
1answer
50 views

How to resume a process from an SSH connection?

At work, I have lot's of interactive scripts running that I would like to access them later on from home. If I do Ctrl+Z to them and then bg, then I am able to use them from home using the fg command. ...
1
vote
1answer
80 views

setpgrp causes tty gone

When using setpgrp vi (and other tty programs) work completely different than if setpgrp is not used. Example: perl -MIPC::Open3 -e '$pid= open3("<&STDIN", ">&STDOUT", ...
0
votes
3answers
72 views

processes started in this session

I've opened a terminal session and started some processes with &. When I tried closing the terminal window, it warned me that there were still jobs running in the background. I can see the ...
0
votes
1answer
162 views

Portable way to kill a process listening on a given port

Is there a way to kill a process listening on a given port (e.g. in bash lsof -t -i tcp:8000 | xargs kill) from a shell script that will also work on cygwin, as well as bash?
2
votes
1answer
411 views

How to start (or find) a process with RUID different from EUID?

Inspired by one of the previously answered questions, I tried executing a program by a user who was not its owner -- and the process's RUID and EUID remained the same. (Unless I read the answer wrong ...
0
votes
1answer
61 views

What is Dynamic interleave for process in Linux?

I have read through the source defined in /source/mm/mempolicy.c. Starting at line 1178: /* Do dynamic interleaving for a process */ static unsigned interleave_nodes(struct mempolicy *policy) { ...
2
votes
2answers
55 views

Replace screen process from within screen

I have configured my shell to exec screen when it starts, unless it's already running within a screen session. So in a TTY, the process tree will look like something like this: ...
4
votes
1answer
274 views

CPU usage of file system operations not shown in top

I run the following command (which does ls for 10,000 times) in a Ubuntu Linux terminal and use the top command to monitor the CPU usage. While top shows the total CPU usage (line 2) is about 48% ...
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vote
2answers
641 views

Spawn multiple processes with a single command

Is there a way to create say 10 instances of a process (for example yes) with a single command? $instantiate 10 yes
2
votes
1answer
185 views

Traverse the Process Tree

I am aware that processes are organized in the form of a hierarchy. So, if I want to implement an operation which is to determine whether a given process belongs to a given sub-tree in the hierarchy ...
0
votes
2answers
135 views

Best way to kill processes in a list

I've got this zsh script. Is there a more a graceful way to do this? export PROCESSES_TO_QUIT='puma rake sidekiq spring rails ruby-debug phantomjs zeus passenger guard resque "node server.js"' pgr() ...
3
votes
1answer
328 views

Command for killing specific PID provided by previous command

Sometimes I need to kill a process (the reasons why are not important). And I know I can find that process with the following command: lsof -i :8080, being my candidate the last process in the output ...
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0answers
583 views

Why does my redhat 5.11 system have so many ext4-dio-unwrit processes?

I have a redhat 5.11 system running, and it looks like there are 32 of these processes. What are they, and why are there so many of them?
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vote
1answer
64 views

process id and command

I want to write the process id and command of all processes with some name and from some user (for example root and init). What should I do? ps -f -u root -C init or ps -f -U root -C init ...
4
votes
2answers
123 views

How to kill a bunch of jobs based on ps output?

Here is output from ps: $ ps aux | grep blob ubuntu 4286 0.0 0.1 34748 9592 ? S Jan14 0:00 /usr/bin/python /usr/local/bin/pynt start_blob_reader ubuntu 4287 0.0 0.1 34748 ...
0
votes
1answer
145 views

I kill process but come back

I have a big problem on centos 6.4 i kill this(8904) but he come back and use the processor. How can we solve? I don't use apache(httpd) on my server. apache don't installed on machine. it's a ...
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0answers
24 views

How to get stdout of process? [duplicate]

I started a process from the command line, but the window server died. However I see the process I started is still running. Is it possible to connect a terminal to the process to see its output? ...
0
votes
1answer
82 views

start process from ssh and be able to close connection [duplicate]

I'm connecting to my RaspberryPi with Raspbian installed via ssh and my problem is, that I can't let the RasPi do things (installing software, make calculations) while my Computer is shut down, since ...
8
votes
1answer
422 views

What three files are always opened by a process?

Someone mentioned that there are three different files that a process always opens. What does this mean? What files are they?
3
votes
1answer
129 views

What could be happening between pidof and kill to cause “no such process”?

I've inherited quite a bit of code and am looking at a cron job that restarts a service once an hour, no other scripts touch this process and this code is ran. #The name of the process has been ...
4
votes
0answers
108 views

Disable networking only inside of a single terminal

I want to run a command in the terminal to disable networking, just in that terminal. How can that be accomplished? I'm running OSX. Note: I only want to disable the networking in that terminal. ...
1
vote
1answer
103 views

How can I monitor network connections for an app

I'm running a chat application on my machine called foo - how do I view all connection attempts (failed or successful) for foo? I have attempted this with netstat, but I am unsure how to associate ...
1
vote
1answer
421 views

Disowned “Stopped” job process still appears in process table

I want to know why after disowning the stopped process, it is still appearing the process table PING www.google.com (74.125.130.106) 56(84) bytes of data. 64 bytes from 74.125.130.106: icmp_seq=1 ...
0
votes
1answer
498 views

Find out home directory of running Oracle instance

There are two oracle directories on our system: oracle oraclex How can I find out which of them is used by the running Oracle instance?
6
votes
2answers
3k views

What are pending signals?

When looking at the limits of a running process, I see Max pending signals 15725 What is this? How can I determine a sensible value for a busy service? Generally, I can't seem to find a ...
2
votes
2answers
289 views

Thin LVM pool frozen due to lack of free space, what to do?

My thin LVM pool got full and some programs hung: device-mapper: thin: 253:4: reached low water mark, sending event. device-mapper: thin: 253:4: no free space available. INFO: task jbd2/dm-6-8:742 ...
2
votes
1answer
89 views

Unrealistically long process times displayed in top

I (partly) manage a small cluster and we are having some problems on a few nodes (running CentOS 6.4). Some processes show exceptionally long run-times in 'top', even though the computer has been ...
1
vote
2answers
71 views

How to keep a process from running?

I can kill a process. But how do I keep that process from being called up again without removing it from Linux? For example, if I run something like netstat to find the port associated with the ...
3
votes
1answer
272 views

Run a command in background that sets env var or define function

> export foo=1 & [1] 9016 [1] + done export foo=1 > echo $foo > I know when running a command with & you spawn a new process and the export foo=1 is not setting env vars in ...
9
votes
4answers
1k views

Why are there many accounts? I'm the only user

I am running an Ubuntu 12.04 desktop system. So far I have only installed some programs (I have sudo rights). When I check the list of users on the system, I see a long list, like more than 20 ...