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

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In htop, what does mean a minus sign before a command?

In htop, I all bash processes have in the command column /bin/bash but one process has in the command column -bash What does it mean?
0
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1answer
39 views

Why does my process take too long to die?

Basically I'm using Linux 2.6.34 on PowerPC (Freescale e500mc). I have a process (a kind of Virtual Machine that was developed in-house) that uses about 2.25 G of mlocked VM. When I kill it, I notice ...
2
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1answer
24 views

list processes belonging to a network namespace

I am on Ubuntu 12.04, and the ip utility does not have ip netns identify <pid> option, I tried installing new iproute, but still, the option identify doesn't seem to be working!. If I were to ...
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0answers
17 views

Inconsistent output on /proc. Can some processes be hidden? [duplicate]

When I list /proc/<PID>, works as expected. But when I use ps or ls /proc | grep <PID>, the process is hidden. How & Why is this possible? [user@host ~]$ ls /proc/12263 attr ...
9
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1answer
853 views

Still alive, still alive after kill -9 / SIGKILL [duplicate]

An apache2 process got stuck on my server and caused problems with other services. (original problem: kerneloops after USB hardware disconnect) root@server:~# ps aux | grep apache2 | grep -v grep ...
2
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1answer
64 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 is ever possible on Linux for a process to be ...
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2answers
41 views

Why is the range of load average not 0-1+ for all cpu's together?

I know that load average is 0-1(or 0-1024) per cpu. E.g a busy quad-core can have a load average of 4.0 or higher. (e.g if there are many tasks). I understand it can be huge like 100+ etc. I also ...
1
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1answer
30 views

How can I find out which mounted filesystems a running process sees?

After having a long debug session and finally finding out that in Fedora (and CentOS) php-fpm has its own mounted /tmp filesystem, which was caused by a systemd setting, PrivateTmp, I am wondering if ...
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0answers
6 views

Page Fault Frequency Algorithm - Compute number of frames and mean resident set

I'm reading about Page Fault Frequency algorithm but I don't understand how can I compute the number of frames. For example I have my reference string: 112233444412412214432255543 and control ...
9
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1answer
69 views

Is it possible to know the source (application) of the clipboard?

I've noticed that sometimes clipboard contents become unavailable if the source application (where the content was copied from) is closed. This leads me to wonder if it's possible to know what the ...
0
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1answer
24 views

Kernel current working directory and inode information placement

I'm reading some doc about UNIX but I don't understand two things: Why is important for the kernel to know the current working directory of the running process? Why not keeping the inode information ...
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6answers
369 views

How to close all proceses without restarting a machine?

I have a lot of processes running and I need to kill them all. How can I do this without restarting a machine?
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1answer
21 views

Stopping jobs by PID?

Could someone tell me why I am unable to kill the jobs below when specifying their PID? I can stop the jobs when using their % id. Mac:~ gd$ ps PID TTY TIME CMD 4523 ttys000 0:00.02 ...
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1answer
35 views

Sending signals to long-running processes (AWK, DD)

I'm familiar that DD command doesn't produce output while running. However, if I send a USR1 signal to it, it can print current state. Can I do the same with AWK? Prints its variables, register ...
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1answer
23 views

Show CPU core usage for parent process and its child processes

Is it possible to display CPU core usage just for a single process and its child processes on Linux?
3
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2answers
52 views

Sum the memory usages of all the processes of a program?

How can we sum the memory usages of all the processes of a program? For example, I have opened many Chrome tabs for webpages, and each tab runs a different process. How can I get the total sum of ...
4
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2answers
304 views

How to locate a Chrome tab from its process PID?

I opened many Chrome tabs for webpages. Each tab has its own PID, e.g. USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND t 3900 1.9 6.3 5718440 508660 ? Sl ...
2
votes
1answer
22 views

How to guard a set of folders from being written into by a specific process?

I would like to have a way in which a set of folders do not allow write access for a particular process. For example, I would love to have a way in which YUM/RPM is not allowed to write into /usr/bin ...
3
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2answers
32 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 ...
3
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3answers
85 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 ...
3
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1answer
38 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
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2answers
49 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
27 views

How do I automatically kill the process and restart it to use the updated package? [closed]

Suppose a process is using a package, and I update it in the midst. How do I create a trigger in Linux that automatically kills the process and restarts it to use the updated package
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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
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4answers
102 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 ...
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3answers
271 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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24 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
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1answer
32 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 ...
5
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1answer
54 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 ...
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2answers
26 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 ...
4
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4answers
232 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
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4answers
71 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 ...
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2answers
78 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 ...
3
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4answers
143 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
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0answers
30 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 ...
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0answers
59 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
38 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 ...
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1answer
31 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
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1answer
42 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. ...
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1answer
30 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", ...
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3answers
29 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
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1answer
58 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?
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1answer
52 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 ...
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1answer
35 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) { ...
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2answers
33 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
58 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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2answers
135 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
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1answer
55 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 ...
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2answers
46 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() ...
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1answer
96 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 ...